Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Operating lease cost	$ 16,828
Sublease (income)	(361)
Net lease cost	$ 16,467	$ 14,500	$ 13,600