Leases - Lease Expense Components (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 11,998	$ 10,120	$ 35,040	$ 29,099
Short-term lease cost	333	370	1,092	1,214
Variable lease cost	830	903	2,548	2,683
Less: sublease income	(346)	(1,140)	(1,633)	(3,363)
Total lease cost, net	12,815	10,253	37,047	29,633
Cash paid for operating leases	12,273	11,514	36,753	32,752
Operating leases	$ 14,741	$ 7,770	$ 55,316	$ 7,770
Weighted-average remaining term (in years) - operating leases	6 years 1 month 17 days		6 years 1 month 17 days		6 years 3 months 14 days
Weighted-average discount rate - operating leases	2.54%		2.54%		2.92%