Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Schedule of Long-Term Debt (Detail)

v3.7.0.1
Long-Term Debt - Schedule of Long-Term Debt (Detail) - USD ($)
$ in Millions
Jun. 30, 2017
Dec. 31, 2016
Debt Instrument [Line Items]    
Convertible senior notes, carrying value of liability component $ 1,047.0 $ 1,024.8
Other 6.4 13.1
Total 2,288.4 1,447.9
Less: current portion 100.3 9.5
Long-term portion 2,188.1 1,438.4
Prior Senior Secured Credit Facility [Member]    
Debt Instrument [Line Items]    
Borrowings under senior secured credit facility, carrying value   $ 410.0
New Senior Secured Credit Facility [Member]    
Debt Instrument [Line Items]    
Borrowings under senior secured credit facility, carrying value $ 1,235.0