Companies in the Dow Jones Industrials (^DJI 0.06%) typically have not only solid profits but also create immense amounts of cash flow, much of which they turn around and return to investors. Through a combination of dividends and share buybacks, Dow companies demonstrate their commitment to treating shareholders right by taking multiple steps that will enhance the value of their investment.

To find out which Dow companies do the most for their investors, I looked at how much cash these companies have returned to shareholders in the form of dividends and share repurchases over the past 12 months, according to the latest available data from S&P Capital IQ. Here are the four companies that rose to the top of the list.

4. Pfizer (PFE -0.12%), $17.8 billion in combined share buybacks and dividends over past 12 months
In the past year, drug giant Pfizer has spent $11.2 billion on share buybacks while also paying out $6.6 billion in dividends. That's especially impressive when you consider that the company has seen some of its biggest blockbuster drugs go off patent recently. But with newly approved blood-thinning drug Eliquis looking like a big performer for the future and other promising prospects in the pipeline, Pfizer should continue to retain the capacity to keep returning money to shareholders well into the future.

3. Johnson & Johnson (JNJ 0.67%), $19.6 billion
Johnson & Johnson weighs in with $6.75 billion in dividends and $12.85 billion in buybacks, but it makes the list on a technicality: its buybacks all come from the money it spent repurchasing shares it issued in its acquisition of Synthes. If you took that out of consideration, then IBM would have made this list with total buybacks and dividends of about $15.4 billion. Unless Johnson & Johnson starts making repurchases more of a part of its capital-return strategy, then the company won't stay among the top Dow stocks by this measure for long.

2. AT&T (T 1.30%), $26.7 billion
By contrast to Johnson & Johnson, AT&T has recommitted itself to buybacks as an important part of returning shareholder capital, having implemented a brand new $11 billion buyback program about two months ago. With the telecom stock having returned $16.6 billion through buybacks and $10.1 billion in dividends over the past 12 months, AT&T's cash flow from its massive wireless network looks like it will remain a powerful source of funding for shareholders for years to come.

1. ExxonMobil (XOM -0.09%), $31.4 billion
ExxonMobil tops the list on both measures, with about $10.4 billion going out in dividends and $21 billion paid on buybacks. Even as other energy companies pay more attention to trying to boost production levels, Exxon has been more content to accept the inevitable aging of its wells, albeit not without some attempts to acquire new assets and find ways to foster growth. Unless oil prices plunge, Exxon should remain able to keep its pace of buybacks and dividends up for the foreseeable future.

Look for companies that treat shareholders right
Investors need to look not only at dividends but also money spent on share repurchases in considering all the measures that a company takes to boost shareholder value. No matter which method a company prefers, both are useful in enhancing the value of your overall investment.