Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term	7 years 2 months 12 days		7 years 2 months 12 days
Operating lease right of use assets	$ 18,600		$ 18,600
Operating lease liabilities	$ 26,962		$ 26,962
Incremental borrowing rate	4.91%		4.91%
Lease cost	$ 1,900	$ 1,700	$ 3,200	$ 3,400
Operating cash flows from operating leases			$ 2,400
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019					$ 6,100
2020					6,500
2021					5,100
2022					3,900
2023					3,500
Thereafter					$ 12,900
Minimum
Lessee, Lease, Description [Line Items]
Remaining initial lease terms			1 year
Term of options to extend	3 years		3 years
Maximum
Lessee, Lease, Description [Line Items]
Remaining initial lease terms			10 years 9 months 18 days
Term of options to extend	15 years		15 years