CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Accounts receivable, Unbilled services with related parties	$ 2.3	$ 2.9
Pre-funded study costs with related parties	3.9	3.7
Advanced billings with related parties	$ 7.6	$ 10.2
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock shares authorized	5,000,000	0
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	60,000,000
Common stock shares issued	40,662,856	32,624,461
Common stock shares outstanding	40,662,856	32,624,461