Financial Instruments - Effect of Company's Derivative Instruments on Net Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Interest Rate Products [Member]
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments, Gain (Loss) Recognized in OCI, (Effective Portion)	$ 3.0	$ (1.5)	$ 0.5	$ 11.1
Interest Expense [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI (Effective Portion)	$ (0.1)	$ (0.1)	$ (0.3)	$ (0.3)

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4D

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624177-113959

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