Leases - Future Minimum Rental Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Future minimum rental payments under noncancelable leases
2019 (excluding the nine months ended September 30, 2019)	$ 1,635
2020	8,799
2021	8,107
2022	5,477
2023	2,964
Thereafter	34,948
Total future minimum lease payments	61,930
Less: Imputed interest	(16,289)
Total	$ 45,641
Future minimum rental payments in accordance with ASC Topic 840, Leases
2019		$ 8,780
2020		8,668
2021		7,961
2022		5,101
2023		2,632
Thereafter		34,638
Total future minimum lease payments		67,780
Less Sublease Income
2019		903
2020		903
2021		892
Total future minimum lease payments		2,698
Net Operating Lease Payments
2019		7,877
2020		7,765
2021		7,069
2022		5,101
2023		2,632
Thereafter		34,638
Total future minimum lease payments		$ 65,082