Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Schedule of Reconciliation of CVR Liability (Detail)

v3.8.0.1
Fair Value Measurements - Schedule of Reconciliation of CVR Liability (Detail) - Level 3 Inputs [Member] - Contingent Value Right [Member]
$ in Millions
3 Months Ended
Mar. 31, 2018
USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]  
Fair value as of December 31, 2017 $ 6.9
Net unrealized loss 11.3 [1]
Fair value as of March 31, 2018 $ 18.2
[1] Unrealized gains and losses related to the revaluation of the CVR are recorded in other expense, net within the Company’s consolidated statements of income.