Long-Term Debt and Short-Term Debt - Schedule of Debt Restated for Adoption of New Accounting Standard (Parenthetical) (Detail) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Borrowings	$ 250,000,000	$ 250,000,000
Audited [Member] | Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Borrowings		250,000,000
Restated [Member] | Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Borrowings		250,000,000
ASU 2015-13 Reclass [Member] | Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Borrowings		250,000,000
Senior Secured Term Loan B [Member]
Debt Instrument [Line Items]
Borrowings	575,000,000	575,000,000
Senior Secured Term Loan B [Member] | Audited [Member]
Debt Instrument [Line Items]
Borrowings		575,000,000
Senior Secured Term Loan B [Member] | Restated [Member]
Debt Instrument [Line Items]
Borrowings		575,000,000
Senior Secured Term Loan B [Member] | ASU 2015-13 Reclass [Member]
Debt Instrument [Line Items]
Borrowings		575,000,000
Senior Secured Revolving Facility [Member]
Debt Instrument [Line Items]
Borrowings	$ 100,000,000	100,000,000
Senior Secured Revolving Facility [Member] | Audited [Member]
Debt Instrument [Line Items]
Borrowings		100,000,000
Senior Secured Revolving Facility [Member] | Restated [Member]
Debt Instrument [Line Items]
Borrowings		100,000,000
Senior Secured Revolving Facility [Member] | ASU 2015-13 Reclass [Member]
Debt Instrument [Line Items]
Borrowings		$ 100,000,000