Stockholders' Equity (Details) - USD ($)							2 Months Ended		11 Months Ended	12 Months Ended
	Jul. 11, 2016	May 09, 2016	Apr. 19, 2016	Feb. 17, 2016	Nov. 12, 2015	Oct. 30, 2015	Jul. 11, 2016	Apr. 19, 2016	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 12, 2017	Sep. 30, 2015	Aug. 20, 2014
Class of Warrant or Right [Line Items]
Authorized amount for stock repurchase program		$ 400,000,000		$ 400,000,000									$ 500,000,000
Authorized amount for accelerated stock repurchase program		$ 400,000,000		$ 400,000,000
Accelerated share repurchased, number of shares purchased (shares)	1,104,162	3,964,812	861,235	4,222,193			5,068,974.000	5,083,428
Average price per share paid for stock repurchased for accelerated stock repurchases (in dollars per share)							$ 78.91	$ 78.69
Repurchased shares (in shares)									3,627,390
Repurchased shares									$ 221,428,000
Repurchased shares (in dollars per share)									$ 61.01
Dividends declared for common stock (in dollars per share)					$ 2.00	$ 2.00				$ 2.97	$ 2.87	$ 2.75
Par value of common stock (in dollars per share)									$ 0.01	$ 0.01	$ 0.01				$ 0.01
Maximum price of common stock available to be issued															$ 500,000,000
2015 Stock Buyback Program
Class of Warrant or Right [Line Items]
Authorized amount for stock repurchase program														$ 1,200,000,000