Summary of Significant Accounting Policies (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Noncontrolling Interest [Member]	Mar. 31, 2014 Common Class B	Mar. 31, 2014 Common Class A	Jun. 30, 2014 Subsequent Event [Member] Common Class A
Noncontrolling Interest [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.33			$ 0.33	$ 0.33	$ 0.35
Noncontrolling interest	$ 385	$ 382
Less: Comprehensive income attributable to noncontrolling interest	10
Non-cash adjustment to non-controlling interest	7
Payments of Dividends			$ (14)