Leases - Components of Lease and supplemental cash flow information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Lease Expense
Operating lease expense	$ 4,857
Short term lease cost	380
Total lease cost	5,237
Cash paid for amounts included in the measurement of operating lease liabilities	4,679
Non-cash lease expense - right-of-use assets	3,672
Right-of-use assets obtained in exchange for operating lease obligations	$ 5,325