CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Accounts receivable, unbilled services with related parties	$ 2.2	$ 2.6
Accounts payable includes related parties	0.1	0.2
Advanced billings with related parties	$ 6.1	$ 6.5
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock shares authorized	5,000,000	5,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock shares authorized	250,000,000	250,000,000
Common stock shares issued	35,926,158	35,519,989
Common stock shares outstanding	35,926,158	35,519,989
Treasury stock shares	185,000	185,000