Fair Values of Derivative Instruments on Condensed Consolidated Balance Sheet (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative financial instruments, Liability	$ 7,600,000	$ 2,600,000
Parent Company [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	2,000,000	2,400,000
Derivative financial instruments, Liability	$ 2,602,000	$ 7,562,000

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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- Definition

Fair value as of the balance sheet date of all interest rate derivative assets designated as cash flow 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 4B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959

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- Definition

Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments.

+ References

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