Financial Instruments Financial Instruments - Interest Rate Swap Agreements (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Derivative, Number of Instruments Held	2
Interest Rate Swap [Member]
Derivative [Line Items]
Notional principal amount, interest rate swap agreement(s)	$ 100.0	$ 150.0
Net payments under derivative swap agreements	1.4	6.2	$ 5.9
USD Interest Rate Swap [Member]
Derivative [Line Items]
Notional principal amount, interest rate swap agreement(s)	$ 50.0
Interest rate swap agreements maturity period	2017
USD Interest Rate Swap Contract One [Member]
Derivative [Line Items]
Derivative, Interest Rate	1.38%
USD Interest Rate Swap Contract Two [Member]
Derivative [Line Items]
Derivative, Interest Rate	1.64%
Us Term Loan [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Effective interest rate on term loans	2.37%
Accrued Liabilities [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Fair value of liability of total outstanding swap agreements	$ 0.7	1.1
Other Liabilities [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Fair value of liability of total outstanding swap agreements	$ 0.1	$ 0.1