Stock Based Compensation Plans (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2002	Jan. 31, 2013	Dec. 31, 2011	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 181	$ 154	$ 101
Total tax benefit recognized related to share-based compensation expense	66	56	37
Unamortized share-based compensation expense related to nonvested equity compensation arrangements	153
Period over which unamortized share-based compensation expense will be amortized.	5 years 0 months
Maximum life of options (in years)	10 years 0 months
Options exercisable at end of period - Common stock		10,204,000	12,759,000
Options exercisable at end of the period - weighted average price		$ 89.46	$ 90.86
Total intrinsic value of options exercised	90	86	37
Cash received from option exercises under all Incentive Plans	215	208	118
Tax benefit realized from option exercises under all Incentive Plans	33	31	14
Shares of common stock available for next year, Granting of options under Incentive Plans	17,997,353
Total common stock authorized for future issuance under equity compensation plans	19,017,057
Treasury stock	2,400,000
Deferred stock units awards granted to non-employee directors	21,490	27,076	25,620
Vesting period for restricted stock/unit awards, lower range	3 years 0 months
Vesting period for restricted stock/unit awards, upper range	5 years 0 months
Weighted-average grant date fair value of incentive performance unit share awards and restricted stock awards granted	$ 80.79	$ 64.77	$ 60.68
Total fair value of incentive/performance unit share and restricted stock/unit awards vested during the year.	119	63	55
Total share-based liability awards paid out during the year	38	29	39
ESPP - shares available for issuance	1,000,000
ESPP - Fair market value purchase rate of common stock (percent)	95.00%
LTIP - Number of committed shares to be released				4,000,000
LTIP - Number of common stock shares transferred				1,100,000
BlackRock Series C Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LTIP - Number of preferred shares acquired in exchange agreement							2,900,000
LTIP - Number of preferred stock shares transferred					200,000	1,300,000
LTIP - Total preferred shares held at end of period	1,300,000
Total - Nonvested Cash Payable Incentive/Performance Units and Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value - liability awards	$ 76