Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lessee, Lease, Description [Line Items]
Lease expense	$ 12,850	$ 13,527
Short term lease expense	342	1,455
Variable lease expense	525	114
Sublease income	(202)	(1,076)
Total operating lease expense	13,515	14,020
Offices
Lessee, Lease, Description [Line Items]
Lease expense	6,314	8,340
Short term lease expense	286	925
Variable lease expense	9	0
Sublease income	(202)	(1,076)
Total operating lease expense	6,407	8,189
Data Centers
Lessee, Lease, Description [Line Items]
Lease expense	6,536	5,187
Short term lease expense	56	530
Variable lease expense	516	114
Sublease income	0	0
Total operating lease expense	$ 7,108	$ 5,831