Leases - Components of Lease and supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lease Expense
Operating lease expense	$ 1,371	$ 1,311
Short term lease cost	115	39
Total lease cost	1,486	1,350
Cash paid for amounts included in the measurement of operating lease liabilities	1,356	1,303
Non-cash lease expense - right-of-use assets	1,036	1,015
Right-of-use assets obtained in exchange for operating lease obligations	$ 65	$ 321