Fair Value (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Financial Assets and Liabilities, Measured at Fair Value Recurring Basis [Table Text Block]

The following table presents a summary of fair value measurements by level and carrying values for items measured at fair value on a recurring basis in the Consolidated Balance Sheets excluding AARP Program-related assets and liabilities, which are presented in a separate table below:

(in millions)	Quoted Prices in Active Markets (Level 1)			Other Observable Inputs (Level 2)			Unobservable Inputs (Level 3)			Total Fair and Carrying Value
December 31, 2014
Cash and cash equivalents	$	7,472		$	23		$	—		$	7,495
Debt securities - available-for-sale:
U.S. government and agency obligations	1,427			193			—			1,620
State and municipal obligations	—			6,668			—			6,668
Corporate obligations	2			7,257			68			7,327
U.S. agency mortgage-backed securities	—			2,056			—			2,056
Non-U.S. agency mortgage-backed securities	—			874			6			880
Total debt securities - available-for-sale	1,429			17,048			74			18,551
Equity securities - available-for-sale	1,200			12			310			1,522
Interest rate swap assets	—			62			—			62
Total assets at fair value	$	10,101		$	17,145		$	384		$	27,630
Percentage of total assets at fair value	37		%	62		%	1		%	100		%
Interest rate swap liabilities	$	—		$	55		$	—		$	55
December 31, 2013
Cash and cash equivalents	$	7,005		$	271		$	—		$	7,276
Debt securities - available-for-sale:
U.S. government and agency obligations	1,750			445			—			2,195
State and municipal obligations	—			6,977			—			6,977
Corporate obligations	25			7,274			36			7,335
U.S. agency mortgage-backed securities	—			2,218			—			2,218
Non-U.S. agency mortgage-backed securities	—			696			6			702
Total debt securities - available-for-sale	1,775			17,610			42			19,427
Equity securities - available-for-sale	1,291			12			269			1,572
Total assets at fair value	$	10,071		$	17,893		$	311		$	28,275
Percentage of total assets at fair value	36		%	63		%	1		%	100		%
Interest rate swap liabilities	$	—		$	163		$	—		$	163

Fair Value Measurements, Nonrecurring [Table Text Block]

The following table presents a summary of fair value measurements by level and carrying values for certain financial instruments not measured at fair value on a recurring basis in the Consolidated Balance Sheets:

(in millions)	Quoted Prices in Active Markets (Level 1)		Other Observable Inputs (Level 2)		Unobservable Inputs (Level 3)		Total Fair Value		Total Carrying Value
December 31, 2014
Debt securities - held-to-maturity:
U.S. government and agency obligations	$	180	$	—	$	—	$	180	$	178
State and municipal obligations	—		—		19		19		19
Corporate obligations	46		10		242		298		298
Total debt securities - held-to-maturity	$	226	$	10	$	261	$	497	$	495
Other assets	$	—	$	478	$	—	$	478	$	484
Long-term debt and other financing obligations	$	—	$	18,863	$	—	$	18,863	$	17,085
December 31, 2013
Debt securities - held-to-maturity:
U.S. government and agency obligations	$	182	$	—	$	—	$	182	$	181
State and municipal obligations	—		—		28		28		28
Corporate obligations	47		9		278		334		334
Total debt securities - held-to-maturity	$	229	$	9	$	306	$	544	$	543
Long-term debt and other financing obligations	$	—	$	16,602	$	—	$	16,602	$	15,745

Reconciliation of Assets Measured at Fair Value on a Recurring Basis Using Level 3 Inputs [Table Text Block]

A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level 3 inputs is as follows:

	December 31, 2014									December 31, 2013									December 31, 2012
(in millions)	Debt Securities			Equity Securities			Total			Debt Securities			Equity Securities			Total			Debt Securities			Equity Securities			Total
Balance at beginning of period	$	42		$	269		$	311		$	17		$	224		$	241		$	208		$	209		$	417
Purchases	32			105			137			38			71			109			11			71			82
Sales	(1		)	(180		)	(181		)	(10		)	(25		)	(35		)	—			(34		)	(34		)
Settlements	—			—			—			—			—			—			(1		)	—			(1		)
Net unrealized gains (losses) in other comprehensive income	1			6			7			(2		)	(7		)	(9		)	—			(14		)	(14		)
Net realized gains (losses) in investment and other income	—			110			110			(1		)	6			5			—			13			13
Transfer to held-to-maturity	—			—			—			—			—			—			(201		)	(21		)	(222		)
Balance at end of period	$	74		$	310		$	384		$	42		$	269		$	311		$	17		$	224		$	241

Fair Value Inputs, Assets, Quantitative Information [Table Text Block]

The following table presents quantitative information regarding unobservable inputs that were significant to the valuation of assets measured at fair value on a recurring basis using Level 3 inputs:

					Range
(in millions)	Fair Value		Valuation Technique	Unobservable Input	Low	High
December 31, 2014
Equity securities - available-for-sale
Venture capital portfolios	$	260	Market approach - comparable companies	Revenue multiple	1.0	6.0
				EBITDAmultiple	8.0	10.0
	50		Market approach - recent transactions	Inactive market transactions	N/A	N/A
Total equity securities      available-for-sale	$	310

AARP Program [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Financial Assets and Liabilities, Measured at Fair Value Recurring Basis [Table Text Block]

The following table presents fair value information about the AARP Program-related financial assets and liabilities:

(in millions)	Quoted Prices in Active Markets (Level 1)		Other Observable Inputs (Level 2)		Total Fair and Carrying Value
December 31, 2014
Cash and cash equivalents	$	415	$	—	$	415
Debt securities:
U.S. government and agency obligations	409		245		654
State and municipal obligations	—		95		95
Corporate obligations	—		1,200		1,200
U.S. agency mortgage-backed securities	—		340		340
Non-U.S. agency mortgage-backed securities	—		177		177
Total debt securities	409		2,057		2,466
Other investments	—		81		81
Total assets at fair value	$	824	$	2,138	$	2,962
Other liabilities	$	5	$	13	$	18
December 31, 2013
Cash and cash equivalents	$	265	$	—	$	265
Debt securities:
U.S. government and agency obligations	426		301		727
State and municipal obligations	—		63		63
Corporate obligations	—		1,145		1,145
U.S. agency mortgage-backed securities	—		414		414
Non-U.S. agency mortgage-backed securities	—		139		139
Total debt securities	426		2,062		2,488
Equity securities - available-for-sale	—		4		4
Total assets at fair value	$	691	$	2,066	$	2,757
Other liabilities	$	3	$	11	$	14