Leases - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Lease, renewal term			5 years
Sublease income	$ 1,700,000	$ 1,800,000	$ 5,200,000	$ 5,300,000
Minimum obligations	$ 803,400,000		803,400,000		$ 842,700,000
Tenant improvements					$ 75,000,000.0
Tenant improvement allowance reimbursement			(19,300,000)	$ (45,400,000)
Rent payments from sub-tenants			24,800,000
Operating leases, not yet commenced, value			$ 107,300,000
Minimum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term			1 year
Operating sublease, term			2 years
Operating leases, not yet commenced, term of contract	5 years		5 years
Maximum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term			16 years
Operating sublease, term			3 years
Operating leases, not yet commenced, term of contract	15 years		15 years
Corporate Headquarters Lease
Lessee, Lease, Description [Line Items]
Tenant improvement allowance reimbursement			$ 15,700,000
Line of Credit | Letter of Credit | Corporate Headquarters Lease
Lessee, Lease, Description [Line Items]
Letter of credit	$ 34,200,000		$ 34,200,000