Summary of Components of Interest as Presented in Consolidated Statements of Operations (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Debt Instrument [Line Items]
Income	$ 5.2		$ 5.3		$ 3.1
Expense on borrowings	(73.8)		(65.5)		(52.2)
UTBs and other tax related interest	0.4		(8.7)		(7.7)
Legacy Tax	4.4	[1]	3.7	[1]	2.5	[1]
Interest capitalized			3.1		1.8
Total	(63.8)		(62.1)		(52.5)
Interest paid	$ 94.4	[2]	$ 67.2	[2]	$ 44.0	[2]

[1] Represents a reduction of accrued interest related to the favorable resolution of Legacy Tax Matters, further discussed in Note 17 to the consolidated financial statements.

[2] Interest paid includes payments of interest relating to the settlement of income tax audits in the first quarter of 2012 as well as net settlements on interest rate swaps more fully discussed in Note 5.