Say "Berkshire Hathaway," and Warren Buffett and Coca-Cola immediately come to mind. Source: Coca-Cola.

Millions of words have been written about Berkshire Hathaway (NYSE:BRK-B) (NYSE:BRK-A), and most of them have been devoted to CEO Warren Buffett. This is understandable, since Berkshire is truly a product of Buffett's guiding hands over the past half-century, turning the small regional textile maker into one of the great investing stories in modern history. 

Berkshire is an amazing collection of companies and stocks that Buffett has acquired over the years, but there's a lot to know about this mega conglomerate. Let's consider seven things you need to know about Berkshire Hathaway. Whether you're a shareholder, considering investing, or just interested in this great company, you might be surprised by some of the things on this list. 

1. Buffett says buying Berkshire was a $200 billion mistake 
Buffett was prepared to sell his stake in what was at the time a struggling textile mill, but when the then-CEO tried to undercut his verbal offer to Buffett, Buffett did something he never does: He let his emotions get the best of him. The result? He bought a controlling stake in the failing business so he could fire the CEO. 

Late-1800s image of Berkshire cotton mill. Source: Wikimedia Commons.

You may think, "well, the rest is history," but that's not really the case. Over the years, the business continued to struggle before Buffett eventually turned it into the holding company that it has become, but not before losing significant money as the business declined. From a 2010 interview with CNBC's Becky Quick:

But the truth is I had now committed a major amount of money to a terrible business. ... So in 1967, when a good insurance company came along, I bought it for Berkshire Hathaway. I really should -- should have bought it for a new entity. Berkshire Hathaway was carrying this anchor, all these textile assets. So initially, it was all textile assets that weren't any good. ... And for 20 years, I fought the textile business before I gave up. If instead of putting that money into the textile business originally, we just started out with the insurance company, Berkshire would be worth twice as much as it is now.

2. Berkshire's subsidiaries are very autonomous
Berkshire Hathaway and its subsidiaries employ more than 330,000 people, but Buffett and the staff at headquarters play essentially no role in regular operations of those subsidiaries. Here's a photo of all of the company's HQ employees, with the exception of two:

Source: Berkshire Hathaway 2013 letter to shareholders.

That's right -- One of the largest companies in the world has 24 people at its headquarters. 

The reasoning is tied to Buffett's philosophy on investing and business operations. When he invests in a company's stock, you can rest assured that he's very confident in the people running the business, and it's no different when Berkshire acquires a company and makes it a subsidiary. Talented and devoted leadership is central to what Buffett looks for, whether he's buying stock, or buying the whole company. 

3. Berkshire's earnings come from a lot of things
Buffett's stock picks get a lot of the press, but it's the income generated by the whole acquisitions that make Berkshire so great. Here's a look at some of Berkshire's income by business segment in 2013:

  • Finance and Financial Products: $985 million.
  • Manufacturing and Retail: $4.2 billion.
  • BNSF Railways: $3.8 billion.
  • Utilities: $1.4 billion.
  • Insurance (underwriting profit): $3 billion.
  • Dividends from stock holdings: $1.4 billion.

While the value of the stock portfolio -- more than $117 billion through 2013 -- is significant, it's the operating businesses that generate the income. 

4. And that's what pays for Berkshire's stock portfolio
The stock portfolio is worth more than double the dollars invested, but the huge returns of the operating businesses are Berkshire's economic driver today. At the end of 2013, the stock portfolio's long-term gains were about $61 billion. In many cases -- like American Express and The Coca-Cola Company -- the value is the result of many decades of returns. 

*From the most recent annual report. The Procter & Gamble stake has since been traded to that company for the Duracell battery business. 

We can all learn from that lesson -- buying shares of great companies and holding them for years -- but for Berkshire, it's the operating businesses that make the whole thing work. 

5. Berkshire's "other" portfolio managers have outperformed Buffett 
In 2010 and 2011, Buffett hired Todd Combs and Ted Weschler as co-investment managers. Through 2013, each manages a portfolio of more than $7 billion, and according to Buffett, they have generated better returns than his investments over the same period. We are only talking about a few years' performance, but both have also outperformed the S&P 500. 

Combs is in his early 40s, while Weschler is 53. Having two young, talented investing minds already handling big money bodes well for Berkshire's future investments. 

6. The insurance business is very important and makes money in two ways

GEICO is only part of Berkshire's huge insurance operations. Source: GEICO

The underwriting profits from the insurance businesses are only part of the story. Just as important is the "float," or the funds that the company receives in premiums, that will be eventually used to pay claims. In the interim, Berkshire can invest this float and turn a profit on it. In 2013, Berkshire's $77 billion in float generated $3.7 billion in after-tax investment income. 

In all, Berkshire's insurance operations generated more than $5.6 billion in after-tax income in 2013, almost 30% of the company's profits. 

7. The company will remain strong when Buffett eventually steps away 
While the "when" remains a mystery,  eventually Buffett will step away. Chances are, the stock will get punished when that day comes, and it shouldn't be surprising that this will happen. The reality is, Buffett has been the guiding forced behind the company for half a century, and his track record speaks for itself. 

But while the stock is likely to take a short-term hit, the business will remain just as solid as it is today. Simply looking at the structure of the company -- the fact that the operating businesses remain autonomous, and all have devoted and talented leaders  -- is a strong indicator that Buffett's departure won't lead to the downfall of the company. 

In 20 years, Buffett's biggest legacy could very well be the continued success of Berkshire. I think Buffett may have said it best: "Someone is sitting in the shade today because someone else planted a tree a long time ago."