Commitments and Contingencies - Narrative (Details) ft² in Thousands, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020 USD ($) ft² building	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Other Commitments [Line Items]
Number of buildings occupied | building	2
Lease liability, current	$ 8,960		$ 9,140
Lease liability, non-current	33,717		36,079
Rent expense	1,600	$ 1,200
Future payments for leases not yet commenced	$ 33,800
Minimum
Other Commitments [Line Items]
Operating leases not yet commenced, term	6 years
Maximum
Other Commitments [Line Items]
Operating leases not yet commenced, term	10 years
Lease One
Other Commitments [Line Items]
Leased square feet | ft²	67
Lease renewal term	5 years
Lease Two
Other Commitments [Line Items]
Leased square feet | ft²	129
Lease renewal term	10 years
Atlanta, Georgia Facilities
Other Commitments [Line Items]
Unoccupied lease charges			$ 400
Lease liability, current	$ 300
Lease liability, non-current	$ 100