Fair Value (Tables)

6 Months Ended

Jun. 30, 2017

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

Schedule of Fair Value, Assets and Liabilities Measured on 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 Condensed Consolidated Balance Sheets:

(in millions)	Quoted Prices in Active Markets (Level 1)			Other Observable Inputs (Level 2)			Unobservable Inputs (Level 3)			Total Fair and Carrying Value
June 30, 2017
Cash and cash equivalents	$	14,533		$	49		$	—		$	14,582
Debt securities - available-for-sale:
U.S. government and agency obligations	2,274			263			—			2,537
State and municipal obligations	—			6,850			—			6,850
Corporate obligations	55			12,273			119			12,447
U.S. agency mortgage-backed securities	—			3,605			—			3,605
Non-U.S. agency mortgage-backed securities	—			995			—			995
Total debt securities - available-for-sale	2,329			23,986			119			26,434
Equity securities	1,707			13			447			2,167
Assets under management	968			2,009			—			2,977
Interest rate swap assets	—			60			—			60
Total assets at fair value	$	19,537		$	26,117		$	566		$	46,220
Percentage of total assets at fair value	42		%	57		%	1		%	100		%
Interest rate swap liabilities	$	—		$	11		$	—		$	11
December 31, 2016
Cash and cash equivalents	$	10,386		$	44		$	—		$	10,430
Debt securities - available-for-sale:
U.S. government and agency obligations	2,017			247			—			2,264
State and municipal obligations	—			7,059			—			7,059
Corporate obligations	21			10,804			102			10,927
U.S. agency mortgage-backed securities	—			2,927			—			2,927
Non-U.S. agency mortgage-backed securities	—			1,002			—			1,002
Total debt securities - available-for-sale	2,038			22,039			102			24,179
Equity securities	1,591			13			437			2,041
Assets under management	1,064			2,041			—			3,105
Interest rate swap assets	—			55			—			55
Total assets at fair value	$	15,079		$	24,192		$	539		$	39,810
Percentage of total assets at fair value	38		%	61		%	1		%	100		%
Interest rate swap liabilities	$	—		$	14		$	—		$	14

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 Condensed 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
June 30, 2017
Debt securities - held-to-maturity:
U.S. government and agency obligations	$	254	$	3	$	—	$	257	$	256
State and municipal obligations	—		—		5		5		5
Corporate obligations	16		2		277		295		295
Total debt securities - held-to-maturity	$	270	$	5	$	282	$	557	$	556
Other assets	$	—	$	474	$	—	$	474	$	472
Long-term debt and other financing obligations	$	—	$	32,289	$	—	$	32,289	$	29,682
December 31, 2016
Debt securities - held-to-maturity:
U.S. government and agency obligations	$	251	$	—	$	—	$	251	$	250
State and municipal obligations	—		—		5		5		5
Corporate obligations	20		8		210		238		238
Total debt securities - held-to-maturity	$	271	$	8	$	215	$	494	$	493
Other assets	$	—	$	476	$	—	$	476	$	471
Long-term debt and other financing obligations	$	—	$	31,295	$	—	$	31,295	$	29,337