Recent Accounting Developments - Future Required Fixed Payments (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Accounting Changes and Error Corrections [Abstract]
Remaining in 2019	$ 19,657
2020	22,596
2021	20,860
2022	20,104
2023	18,084
2024	17,167
2025 and thereafter	146,202
Total minimum future amounts	264,670
Impact of measuring the lease liability on a discounted basis	(67,817)
Total lease liability	$ 196,853