Income Taxes (Details) - USD ($)	3 Months Ended			12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 31,174,000		$ 28,528,000
Effective tax rate	24.00%		27.30%
Deferred tax liability, provisional income tax benefit		$ 40,600,000
Accumulated foreign earnings, provisional liability	$ 30,400,000	$ 30,300,000		$ 30,300,000
Transition tax for accumulated foreign earnings, increase (decrease) in provisional income tax expense	100,000
Provisional increase, deferred tax liability, income tax (expense) benefit				9,200,000
Adjustment, deferred income tax expense (benefit)				9,200,000
Permanent reinvestment, deferred tax liability, income tax (expense) benefit				$ 8,200,000
Minimum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible change in unrecognized tax benefits over next 12 months	0
Maximum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible change in unrecognized tax benefits over next 12 months	$ 1,500,000