Net Income Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator for Basic and Diluted Earnings per Share - [Abstract]
Net Income	$ 444,588		$ 1,103,618		$ 706,353		$ 660,928		$ 580,194		$ 462,498		$ 659,692		$ 494,725		$ 2,915,487	$ 2,197,109	$ 570,279
Denominator for Basic Earnings per Share - [Abstract]
Weighted Average Shares (in shares)																	543,443,000	540,341,000	535,155,000
Potential Dilutive Common Shares -[Abstract]
Stock Options/SARs (in shares)																	2,526,000	2,316,000	2,911,000
Restricted Stock/Units and Performance Units/Stock (in shares)																	2,570,000	3,570,000	3,458,000
Denominator for Diluted Earnings per Share - [Abstract]
Adjusted Diluted Weighted Average Shares (in shares)	549,153,000		549,518,000		548,676,000		548,071,000		547,966,000		547,152,000		545,477,000		544,526,000		548,539,000	546,227,000	541,524,000
Net Income Per Share [Abstract]
Basic (in dollars per share)	$ 0.82	[1]	$ 2.03	[1]	$ 1.30	[1]	$ 1.22	[1]	$ 1.07	[1]	$ 0.85	[1]	$ 1.22	[1]	$ 0.92	[1]	$ 5.36	$ 4.07	$ 1.07
Diluted (in dollars per share)	$ 0.81	[1]	$ 2.01	[1]	$ 1.29	[1]	$ 1.21	[1]	$ 1.06	[1]	$ 0.85	[1]	$ 1.21	[1]	$ 0.91	[1]	$ 5.32	$ 4.02	$ 1.05
Antidilutive Stock Options and SARs excluded from Diluted Earnings Per Share Calculation (in shares)																	700,000	300,000	500,000

[1] The sum of quarterly net income (loss) per share may not agree with total year net income (loss) per share as each quarterly computation is based on the weighted average of common shares outstanding.