Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings from Continuing Operations before Income Taxes [Abstract]
United States	$ 143,924	$ 124,500	$ 146,940
Foreign	135,141	151,457	158,506
Earnings before income taxes	279,065	275,957	305,446
Current tax expense (benefit):
Federal	112,673	36,771	35,029
State	5,035	5,785	6,074
Foreign	19,689	64,109	19,884
Current income tax expense (benefit)	137,397	106,665	60,987
Deferred tax expense (benefit):
Federal	34,857	1,404	10,752
State	473	267	1,052
Foreign	(885)	995	(9,031)
Deferred income taxes	25,968	5,613	2,863
Deferred Income Tax Expense (Benefit), Excluding Discontinued Operations	34,445	2,666	2,773
Total provision	$ 171,842	$ 109,331	$ 63,760