When Apple (NASDAQ:AAPL) announced its three-year capital return program in 2012, the company made it clear that dividends and share repurchases would be a priority in the coming years. Management planned to return $45 billion to shareholders during this period. But this was just the beginning of what would expand into the world's largest capital return program in history.

After repeatedly increasing the scope of its capital return program since it was initiated in 2012, Apple's total cash returned to shareholders through dividends and repurchases by the end of fiscal 2017 amounted to an incredible $234 billion.

Here's what investors should know about Apple's aggressive capital return program.

CEO Tim Cook at Apple's iPhone 7 launch

Apple CEO Tim Cook. Image source: Apple.

1. The program is heavily weighted toward repurchases.

Since initiating its capital return program in 2012, capital returned each year has skewed heavily toward repurchases. Of the $234 billion returned to shareholders during this period, about $61 billion went to dividends, and $173 went to share purchases. In other words, about 74% of Apple's capital return program has gone toward share repurchases.

These repurchases have given Apple's earnings-per-share growth a significant boost. Since Apple's capital return program was announced, trailing-12-month net income has increased 25%, while trailing-12-month earnings per share has risen 57%. This has been driven by an approximately 22% decrease in shares outstanding during this period.

AAPL Net Income (TTM) Chart

AAPL Net Income (TTM) data by YCharts.

2. Annual capital returned peaked in 2014.

While the total authorized amount and the timeline for the authorization for Apple's capital return program has increased significantly since 2012, Apple's annual amount of cash returned to shareholders actually peaked in fiscal 2014. During fiscal 2014, Apple returned more than $57 billion to shareholders through dividends and repurchases. In fiscal 2017, Apple returned nearly $48 billion.

3. Apple has acted opportunistically.

It would be difficult to criticize Apple's capital return program, as the company has executed its share repurchases opportunistically.

Broadly, Apple's decision to focus primarily on share repurchases instead of dividends with its capital return program looks like a smart decision in hindsight. With shares climbing to new highs recently, up 50% in the past 12 months and 132% in the past five years, the bulk of Apple's repurchases arguably took place when the stock was meaningfully undervalued.

But Apple has also acted opportunistically on more specific buying opportunities when shares were trading at an exceptionally deep discount. When the stock pulled back in fiscal 2014, for example, Apple initiated $21 billion of accelerated repurchases on top of its $24 billion of open market repurchases during the period. This brought total repurchases during the year to a whopping $45 billion -- far higher than repurchases in any other year. For comparison, Apple repurchased $33 billion in fiscal 2017.

AAPL Chart

AAPL data by YCharts.

For a more specific example of Apple's good stewardship with repurchases, consider when the tech giant bought $14 billion worth of its own shares during a two-week period following quarterly financial results that disappointed Wall Street in early 2017, sending shares about 8% lower after the report. Cook told The Wall Street Journal he wanted to be "aggressive" and "opportunistic." The stock was trading around $73 at the time, compared to Apple's $174 stock price today.

4. Apple's aggressive capital return program is here to stay.

Investors should expect Apple's aggressive capital return program to continue. In May, Apple expanded its total cumulative authorization from $250 billion to $300 billion, giving the program an expiration date of the end of March 2019.

Further, Apple's record $269 billion of cash plus marketable securities and its $51 billion of free cash flow in fiscal 2017 can easily support more repurchases and dividends. And Apple's strong return to growth in fiscal 2017 should help, too.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.