Fair Value of Financial Instruments - Schedule of Interest Rate Swaps Outstanding (Detail) - Interest Rate Swaps [Member] $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Aggregate Notional Amount	$ 659,309	$ 659,309
Gross Asset at Fair Value	5,611	5,611
Gross Liability at Fair Value	10,997	10,997
Gross Gains	440	2,989
Gross Losses	$ 1,641	$ 12,836

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

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

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Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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

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