Berkshire Hathaway's (BRK.A -0.39%) (BRK.B -0.20%) third-quarter operating earnings declined to $3.44 billion, down from $4.85 billion in the year-ago period, due primarily to large insurance underwriting losses from natural disasters. Third-quarter weather events were particularly troublesome for Berkshire Hathaway Reinsurance, which posted a massive $1.3 billion pre-tax underwriting loss in the third quarter.

Here's a look into Berkshire's third-quarter results, segment by segment.

Insurance -- $395 million net loss

Hurricanes Harvey, Irma, Maria and an earthquake in Mexico exacted a high price from Berkshire Hathaway's insurers. In all, the company reported that these four weather events generated $3 billion of losses across its insurance companies.

The impact was widespread, as all but one of its insurance units posted an underwriting loss. In the third quarter of 2016, the situation was reversed, as all but one insurer posted an underwriting profit.

Insurer

Pre-tax underwriting profit (loss)

GEICO

($416 million)

General Re

($504 million)

Berkshire Hathaway Reinsurance Group

($1.34 billion)

Berkshire Hathaway Primary Group

$52 million

Source: Berkshire Hathaway's quarterly SEC filing.

Berkshire Hathaway Reinsurance Group was the biggest loser. An insurer for insurance companies, BH Reinsurance pays the price for catastrophic weather and outsized insurance-industry losses. This quarter, BH Reinsurance reported a $927 million loss from property and casualty policies. In all, the reinsurance company incurred $1.45 billion of losses from the three hurricanes and earthquake in Mexico.

GEICO was also hit hard by Hurricanes Harvey and Irma, estimating it incurred losses of approximately $500 million -- 6.6% of premiums earned -- from the two storms. That said, GEICO does have one thing to boast about: Its premium growth has been nothing short of remarkable. Earned premiums grew 16.5% year over year, to $7.5 billion, an incredible achievement given it's already the second-largest car insurer in the United States.

In total, Berkshire Hathaway's insurers posted a $1.4 billion loss from underwriting during the third quarter, partially offset by roughly $1 billion in investment profits, thus resulting in a $395 million loss for the quarter. The occasional large underwriting loss is simply the price Berkshire pays for the rights to the investment profits on its $113 billion of combined insurance float. It's a price worth paying, as in most years, Berkshire earns a profit on its underwriting, which only adds to the billions it earns from investing the float.

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Manufacturing, service, and retailing -- $1.7 billion profit

Berkshire's collection of varied operating businesses from Precision Castparts to Dairy Queen do most of the heavy lifting in each earnings report, and is now Berkshire's largest segment in terms of profit. Berkshire's industrial-products companies are the most profitable, generating pre-tax profits of $1.25 billion on $6.7 billion of revenue this quarter. Revenue for this group improved by $257 million, or about 4% year over year, with Marmon and IMC producing the largest revenue increases on a percentage basis.

In services, NetJets was named as a contributor to revenue growth, as the company saw higher aircraft sales and a 5% year-to-date increase in flight hours. Berkshire's retailers experienced a combined 0.6% revenue increase in the third quarter and a 22% increase in pre-tax profits. Note that revenue in the retail segment is mostly driven by Berkshire Hathaway Automotive, formerly known as Van Tuyl, which made up 64% of retail revenue this quarter.

BNSF railroad hauls it in -- $1 billion profit

Berkshire's BNSF railroad saw its revenue and profit rise in the third quarter. Revenue grew to $5.3 billion in the third quarter, a 2.8% improvement from the year-ago period. Net earnings rose to $1.04 billion, up only modestly from the $1.02 billion BNSF earned in the third quarter of 2016.

Higher volume and pricing drove revenue and profit growth. Notably, freight revenue from consumer products jumped by 7.6% year over year, helped by a 7.4% increase in volume and a smaller increase in pricing. Freight revenue from industrial products rose 4%, and revenue from coal jumped 5.9% in the third quarter. Agricultural revenue was the only category to show a revenue decline (9.4% drop), which Berkshire attributed to lower grain exports.

Utilities and energy -- $963 million profit

Operating under the Berkshire Hathaway Energy umbrella, the utility and energy businesses are the most dependable profit generators. The bulk of revenue and profit at Berkshire Hathaway Energy comes from regulated utility assets, which enjoy stable demand and government-regulated prices that ensure the utility earns a reasonable return on capital invested in power plants.

Combined earnings before interest and taxes at PacificCorp, MidAmerican Energy, and NV Energy, which own regulated utility assets and are the largest pieces of the utilities and energy group, rose to $986 million during the third quarter, up 3.6% from the year-ago period. Net earnings from Berkshire Hathaway's energy portfolio tallied to $963 million this quarter, a 3.3% improvement year over year. 

Finance and financial products -- $341 million profit

The star here is Berkshire Hathaway's Clayton Homes, a company that produces, sells, and finances manufactured homes. Clayton Homes' revenue rose 20%, and pre-tax profits increased 5%, due to higher home sales and a greater mix of site-built homes. (Site-built homes have lower margins, as land is included in the sales price.)

Berkshire's profits from leasing transportation equipment and furniture, and its share of earnings from a commercial mortgage-servicing business, declined in the third quarter. Berkshire noted that "industry railcar capacity available for lease exceeds demand," explaining that it's seeing lower lease rates for railcars. CORT Furniture's lower earnings were only partially offset from higher Berkadia earnings, the joint venture with Leucadia National that services commercial mortgages.

Berkshire cash pile -- $109 billion

Berkshire is flush with cash, ending the quarter with $109 billion of cash and cash equivalents. Warren Buffett has said that he's struggling to put the conglomerate's excess cash to work, as the company generates cash faster than he can spend it on new acquisitions.

With the cash pile growing, many have speculated Berkshire may soon embark on its biggest acquisition ever, or be forced to start regularly returning cash to shareholders. At the annual shareholders meeting, Charlie Munger suggested he'd be comfortable with an acquisition as large as $150 billion, partially financed by debt. Buffett laughed at Munger's answer, suggesting he'd be comfortable with a smaller number, but the truth is that there are very few businesses Berkshire couldn't afford to buy.