Related Party Transactions - Other (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) ft² property	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Related Party Transaction [Line Items]
Area of real estate property (in sqft)	10,100,000
Undivided Interest
Related Party Transaction [Line Items]
Area of real estate property (in sqft)	5,447
Chairman emeritus | Leased space rental
Related Party Transaction [Line Items]
Number of properties | property	1
Lease cancellation, period of notice (in days)	90 days
Percentage of lease space occupied by Chairman emeritus and employee	15.00%
Revenue from related parties, net of payment for pro rata share of leased space | $	$ 0.3	$ 0.3	$ 0.3