Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax provision (benefit)	$ 7,742	$ 7,652	$ 7,432	$ 5,117
Effective income tax rate	26.60%	(40.10%)	27.70%	(20.80%)
Provisional discrete net tax benefit recorded as result of changes in tax law					$ 73,500
Provisional net tax expense for one-time transition tax recorded as result of changes in tax law					1,400
Provisional net tax benefit recorded for revaluation of deferred tax assets and liabilities as result of changes in tax law					$ 74,900