Leases - Lease Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Lease cost
Total operating lease cost	$ 4,794
Depreciation of leased assets	1,348
Interest on lease liabilities	5,155
Total finance lease cost	6,503
Total lease cost	11,297
Short-term lease and variable lease costs	900
Service
Lease cost
Total operating lease cost	2,315
Research and development
Lease cost
Total operating lease cost	313
Sales and marketing
Lease cost
Total operating lease cost	1,378
General & administrative
Lease cost
Total operating lease cost	$ 788