Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Dilutive Impact of Common Stock Equivalents on Earnings per Share (Abstract]
Net income	$ 368,582	$ 364,752	$ 824,967	$ 798,179
Basic earnings per share [Abstract]
Earnings available to common shareholders	368,582	364,752	824,967	798,179
Weighted average common shares outstanding - basic (in shares)	506,082	498,149	502,983	495,256
Earnings available to common shareholders - basic (in dollars per share)	$ 0.73	$ 0.73	$ 1.64	$ 1.61
Effect of dilutive securities [Abstract]
Time based equity awards	283	492	230	511
Diluted earnings per share [Abstract]
Earnings available to common shareholders	$ 368,582	$ 364,752	$ 824,967	$ 798,179
Weighted average common shares outstanding - diluted (in shares)	506,365	498,641	503,213	495,767
Earnings available to common shareholders - diluted (in dollars per share)	$ 0.73	$ 0.73	$ 1.64	$ 1.61