Leases - Summary of Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Lessee Lease Description [Line Items]
Operating lease right of use assets, gross	$ 158,827	$ 159,454
Amortization of right-of-use assets	(54,904)	(32,322)
Total operating lease right-of-use assets	103,923	127,132
Real Estate Facilities
Lessee Lease Description [Line Items]
Operating lease right of use assets, gross	156,020	157,010
Office Equipment
Lessee Lease Description [Line Items]
Operating lease right of use assets, gross	2,117	1,864
Other
Lessee Lease Description [Line Items]
Operating lease right of use assets, gross	$ 690	$ 580