Leases Leases - Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lease, Cost [Abstract]
Fixed costs	$ 8,496	$ 8,245
Variable costs	15	13
Short-term lease costs	256	92
Sublease income	(1,099)	(1,016)
Net lease expense	7,668	7,334
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	9,278	8,236
ROU assets obtained in exchange for lease obligations:
Operating leases	$ 10,482	$ 4,560