Stockholders' Equity - Narrative (Details) - USD ($) shares in Millions	1 Months Ended	3 Months Ended
	Feb. 28, 2014	Mar. 31, 2016	Mar. 31, 2015	Feb. 29, 2016	Oct. 31, 2013
Class of Stock [Line Items]
Stock repurchase program, authorized amount				$ 1,000,000,000	$ 750,000,000.0
Repurchases of common stock	$ (62,000,000)	$ (108,725,000)	$ (62,680,000)
Amortization expense from capitalized stock-based compensation		$ 3,300,000	$ 3,000,000
Common Stock [Member]
Class of Stock [Line Items]
Shares repurchased during period (in shares)		2.2
Repurchases of common stock		$ (108,700,000)