Effect of Revision on Previously Reported Amounts (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Effect of revision on net cash provided by (used in) operating activities, net	$ 4.4
Effect of revision on net cash provided by (used in) financing activities	(4.4)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Effect of revision on net cash provided by (used in) operating activities, net	(4.4)
Effect of revision on net cash provided by (used in) financing activities	$ 4.4