Stock-Based Compensation- Restricted Stock and Restricted Stock Units Activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested shares outstanding, Beginning balance	2,809,000	2,480,000	2,494,000
Granted	2,728,000	1,773,000	1,144,000
Forfeited	(637,000)	(378,000)	(233,000)
Vested	(1,195,000)	(1,066,000)	(925,000)
Non-vested shares outstanding, Ending balance	3,705,000	2,809,000	2,480,000
Non-vested shares outstanding, Weighted Average Grant Date Fair Value per Share, Beginning balance	$ 43.31	$ 49.52	$ 36.84
Granted, Weighted Average Grant Date Fair Value per Share	$ 27.24	$ 35.29	$ 64.35
Forfeited, Weighted Average Grant Date Fair Value per Share	$ 39.47	$ 47.34	$ 44.79
Vested, Weighted Average Grant Date Fair Value per Share	$ 39.64	$ 41.70	$ 34.86
Non-vested shares outstanding, Weighted Average Grant Date Fair Value per Share, Ending balance	$ 33.31	$ 43.31	$ 49.52
Service - Based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested shares outstanding, Beginning balance	2,371,000	2,123,000	2,178,000
Granted	2,428,000	1,589,000	1,014,000
Forfeited	(605,000)	(364,000)	(233,000)
Vested	(1,195,000)	(977,000)	(836,000)
Non-vested shares outstanding, Ending balance	2,999,000	2,371,000	2,123,000
Performance Market Based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested shares outstanding, Beginning balance	438,000	357,000	316,000
Granted	300,000	184,000	130,000
Forfeited	(32,000)	(14,000)	0
Vested	0	(89,000)	(89,000)
Non-vested shares outstanding, Ending balance	706,000	438,000	357,000