Income Taxes - Pretax Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Examination [Line Items]
Income from continuing operations before income taxes	$ 43,792	$ 70,200	$ 55,610	$ 30,378	$ 37,804	$ 62,268	$ 52,879	$ 31,034	$ 199,980	$ 183,985	$ 173,758
U.S.
Income Tax Examination [Line Items]
Income from continuing operations before income taxes									168,692	151,209	138,616
Outside the U.S.
Income Tax Examination [Line Items]
Income from continuing operations before income taxes									$ 31,288	$ 32,776	$ 35,142