Consolidated Statements of Stockholders' Equity (USD $) In Millions, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2011	$ 6,867	$ 2	$ 4,902	$ 58	$ 1,777	$ 128
Common Stock, Shares, Beginning period at Dec. 31, 2011		1,506
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributions from (Distributions to) Noncontrolling Interest	131					131
Net Income (Loss)	2,574				2,592	(18)
Other Comprehensive Income (Loss)	(104)		0	(104)
Issuances Under Employee Stock Purchase Plan, Shares		2
Issuances Under Employee Stock Purchase Plan, Value	31		31
Issuances Under Equity Incentive plan, Shares		32
Stock-Based Compensation	436		436
Tax Benefits from Employee Stock Plans	113		113
Stock-Based Compensation	208		208
Repurchases of Common Stock, Shares		(21)
Repurchases of Common Stock, Value	(705)		(41)		(664)
Convertible Notes Settlement	(214)		(214)
Purchases of convertible note hedges	0
Convertible Notes Hedge Settlement	(214)		(214)
Reclassification to equity component of currently redeemable convertible notes	7		7
Ending Balance at Dec. 31, 2012	9,544	2	5,642	(46)	3,705	241
Common Stock, Shares, Ending period at Dec. 31, 2012		1,519
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributions from (Distributions to) Noncontrolling Interest	152		0			152
Net Income (Loss)	3,057		0		3,075	(18)
Other Comprehensive Income (Loss)	(78)		0	(78)
Issuances Under Employee Stock Purchase Plan, Shares		3
Issuances Under Employee Stock Purchase Plan, Value	55		55	0
Issuances Under Equity Incentive plan, Shares		24
Stock-Based Compensation	258		258	0
Tax Benefits from Employee Stock Plans	285		285	0
Stock-Based Compensation	254		254
Repurchases of Common Stock, Shares		(12)
Repurchases of Common Stock, Value	(688)		(14)		(674)
Warrants Settlement	(1,040)		(1,040)
Convertible Notes Settlement	(2,771)		(2,771)
Adjustment to APIC, Convertible Note Hedge Settlement			2,774
Purchases of convertible note hedges	0
Convertible Notes Hedge Settlement	(2,774)
Reclassification to equity component of currently redeemable convertible notes	(57)		(57)
Ending Balance at Dec. 31, 2013	11,745	2	5,386	(124)	6,106	375
Common Stock, Shares, Ending period at Dec. 31, 2013	1,534	1,534
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributions from (Distributions to) Noncontrolling Interest	60					60
Net Income (Loss)	12,059				12,101	(42)
Other Comprehensive Income (Loss)	425			425
Issuances Under Employee Stock Purchase Plan, Shares	2	3
Issuances Under Employee Stock Purchase Plan, Value	72		72
Issuances Under Equity Incentive plan, Shares		24
Stock-Based Compensation	260		260
Tax Benefits from Employee Stock Plans	484		484
Stock-Based Compensation	362		362
Repurchases of Common Stock, Shares		(62)
Repurchases of Common Stock, Value	(5,608)		(133)		(5,475)
Warrants Settlement			(4,093)
Convertible Notes Settlement	(2,513)		(2,513)
Adjustment to APIC, Convertible Note Hedge Settlement	2,543		2,543
Purchases of convertible note hedges	26		26
Convertible Notes Hedge Settlement	(4,093)
Reclassification to equity component of currently redeemable convertible notes	49		49
Ending Balance at Dec. 31, 2014	$ 15,819	$ 2	$ 2,391	$ 301	$ 12,732	$ 393
Common Stock, Shares, Ending period at Dec. 31, 2014	1,499	1,499