Effect of Derivative Instruments on Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Designated as Hedging Instrument [Member] \| Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Loss Reclassified from Accumulated OCI into Income (Effective Portion)	$ (1,131)	$ (1,791)	$ 2,317	$ 3,983
(Loss) Gain on Cash Flow Hedge Ineffectiveness, Net	(120)	(12)	(163)	(73)
Designated as Hedging Instrument [Member] \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) or Gain Recognized in OCI on Derivative (Effective Portion)	(1,314)	1,804	(5,019)	(2,543)
Not Designated as Hedging Instrument [Member] \| Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, (Loss) Gain Recognized in Income, Net	$ 0	$ 0	$ 0	$ (3)

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a),(c),(d),(e)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

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

+ References

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=56946850&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=56946850&loc=SL5624177-113959

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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

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