Equity (Details) - USD ($) $ / shares in Units, shares in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Dividends Payable [Line Items]
Common Stock, Dividends, Per Share, Cash Paid	[1]	$ 0.950
Dividends, Common Stock, Cash	[1]	$ 343,300,000
Common stock repurchased during period, shares		0.2
Purchases of capital stock		$ 22,005,000	$ 24,354,000
Common Stock [Member]
Dividends Payable [Line Items]
Dividends Payable, Date Declared	[1]	Feb. 17, 2017
Dividends Payable, Date to be Paid	[1]	Mar. 31, 2017
Dividends Payable, Date of Record	[1]	Mar. 17, 2017
At the Market Program [Member]
Dividends Payable [Line Items]
Payments of Stock Issuance Costs		$ 200,000

[1] Inclusive of dividends accrued for holders of unvested restricted stock units, which are paid at the time the restricted stock units vest.