Schedule of Gains (Losses) for Derivatives Designated as Fair Value Hedges (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the condensed consolidated statements of operations	$ 0.3	$ 0.8	$ 0.9	$ (0.2)
Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the condensed consolidated statements of operations	13.3	(8.7)	17.6	(3.5)
Hedged Items
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the condensed consolidated statements of operations	$ (13.0)	$ 9.5	$ (16.7)	$ 3.3

Net gain (loss) recognized in earnings during the reporting period representing the amount of the fair value of the hedges' ineffectiveness.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 25

-Section 50

-Paragraph 1

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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