Leases - Lease Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Finance lease costs:
Amortization of right-of-use assets	$ 1,387
Interest on lease liabilities	160
Operating lease costs	9,326
Variable lease costs	2,949
Short-term lease costs	1,656
Total lease costs	$ 15,478