Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases
Cash paid for amounts included in the measurement of lease liabilities	$ 1,387	$ 1,978
Right-of-use assets obtained in exchange for new lease liabilities (noncash)	$ 2,022	$ 144