Fair Value Measurements - Fair Value of Assets and Liabilities on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014
Total Fair Value and Carrying Value on Balance Sheet
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Interest rate swap, Assets	$ 0.4
Level 2
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Interest rate swap, Assets	0.4
Interest Rate Swap Agreements
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities		3.4
Interest Rate Swap Agreements | Total Fair Value and Carrying Value on Balance Sheet
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities		3.4
Interest Rate Swap Agreements | Level 2
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities		3.4
Contingent Consideration | Total Fair Value and Carrying Value on Balance Sheet
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities		1.3
Contingent Consideration | Level 3
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities		$ 1.3