Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments And Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases

Year ending December 31,	(in thousands)
2018	$	36,238
2019		34,223
2020		31,459
2021		31,091
2022		29,761
Thereafter		30,998
	$	193,770

Operating Leases of Lessee Disclosure

(in thousands)	2017			2016			2015
Rent	$	36,269		$	39,537		$	40,009
Sublease income		(142	)		(147	)		(32	)
Total rent expense	$	36,127		$	39,390		$	39,977