Leases - Future Lease Payments under Non-Cancellable Leases (Details) - USD ($) $ in Thousands		Jun. 30, 2019		Dec. 31, 2018
Leases [Abstract]
2019	[1]	$ 11,890
2020	[1]	22,922
2021	[1]	20,983
2022	[1]	18,538
2023	[1]	16,333
Thereafter	[1]	86,345
Total undiscounted lease payments	[1]	177,011
Less: imputed interest	[1]	(69,812)
Total lease liabilities	[1]	107,199
2019	[1]	4,211
2020	[1]	7,588
2021	[1]	6,829
2022	[1]	6,697
2023	[1]	6,681
Thereafter	[1]	57,330
Total undiscounted lease payments	[1]	89,336
Less: imputed interest	[1]	(33,892)
Total lease liabilities		$ 55,444	[1]	$ 55,282

[1] Amounts are exclusive of lease arrangements that are classified in Liabilities Held for Sale.