Stockholders' Equity (Narrative) (Details) - USD ($) shares in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Oct. 31, 2016
Stockholders Equity Note [Line Items]
Stock-based compensation expense	$ 2,065,000,000	$ 1,500,000,000
Awards expected to be settled with stock	2,009,000,000	1,494,000,000
Repurchases of capital stock paid in cash	$ 1,127,000,000	$ 2,098,000,000
October 2016 Share Repurchase Program | Class C Capital Stock
Stockholders Equity Note [Line Items]
Authorized share repurchase amount			$ 7,019,340,976.83
Repurchases of capital stock (in shares)	1.5
Repurchases of capital stock	$ 1,200,000,000
Repurchases of capital stock paid in cash	1,100,000,000
Restricted Stock Units (RSUs)
Stockholders Equity Note [Line Items]
Unrecognized compensation cost	$ 16,300,000,000
Weighted average recognition period for unrecognized stock-based compensation expense	2 years 8 months