Other accrued expenses and other non-current liabilities - Other non-current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Other non-current liabilities
Leasehold obligation incentive		$ 7,600	$ 7,572
Deferred Rent		$ 3,000	3,011
Deferred tax liabilities	$ 2,498		2,816
Other	6		8
Total non-current liabilities	$ 2,504		$ 13,407