Stock Repurchase Programs - Additional Information (Details) - USD ($)	1 Months Ended			9 Months Ended
	Jul. 31, 2016	Jun. 30, 2015	Jan. 31, 2015	Sep. 30, 2016
Equity, Class of Treasury Stock [Line Items]
Authorization of additional plan				$ 2,500,000,000
Stock Repurchase Program January 2015
Equity, Class of Treasury Stock [Line Items]
Authorization of additional plan			$ 2,000,000,000
Stock Repurchase Program June 2015
Equity, Class of Treasury Stock [Line Items]
Authorization of additional plan		$ 1,000,000,000
Stock Repurchase Program July 2016
Equity, Class of Treasury Stock [Line Items]
Authorization of additional plan	$ 2,500,000,000