Leases - Maturity of Lease Liabilities (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Leases [Abstract]
2019, excluding the three months ended March 31, 2019	$ 7,932
2020	11,919
2021	11,408
2022	10,635
2023	9,678
Thereafter	21,255
Total lease payments	72,827
Less: Interest	(24,892)
Present value of lease liabilities	$ 47,935