Leases - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease renewal term	5 years
Lease asset impairments and other charges	$ 12,121,000	$ 0	$ 0
Right-of-use assets recorded upon adoption	105,845,000	125,822,000
Operating lease liabilities recorded upon adoption	131,388,000	130,997,000
Rental expense for operating leases classified under ASC 840		21,000,000.0
Sublease income	2,600,000	$ 3,500,000	$ 2,800,000
Estimated aggregate sublease income to be received in the future	4,500,000
COVID-19
Lessee, Lease, Description [Line Items]
Lease asset impairments and other charges	2,100,000
Cumulative Effect, Period of Adoption, Adjustment
Lessee, Lease, Description [Line Items]
Right-of-use assets recorded upon adoption				$ 72,000,000.0
Operating lease liabilities recorded upon adoption				$ 75,000,000.0
Building
Lessee, Lease, Description [Line Items]
Lease asset impairments and other charges	12,100,000
Leasehold improvements
Lessee, Lease, Description [Line Items]
Lease asset impairments and other charges	$ 3,600,000
Minimum
Lessee, Lease, Description [Line Items]
Operating lease terms	3 years
Maximum
Lessee, Lease, Description [Line Items]
Operating lease terms	5 years