Leases - Net Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lessee, Lease, Description [Line Items]
Net lease costs	$ (14,865)	$ (16,786)	$ (15,389)
Variable lease costs	1,600	600	400
Other general and administrative
Lessee, Lease, Description [Line Items]
Operating lease costs	(19,502)	(17,183)	(15,780)
Other revenue
Lessee, Lease, Description [Line Items]
Sublease revenue	$ 4,637	$ 397	$ 391