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Derivative Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2016	Jun. 24, 2016
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount	$ 350,000,000		$ 350,000,000
Realized (gains) losses on interest rate hedges reclassified to earnings	132,000
Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount	$ 150,000,000
Derivative, maturity date	Jun. 17, 2021
Cash Flow Hedge
Derivative Instruments Gain Loss [Line Items]
Derivative, strike rate for the interest rate swap contract				1.145%
Cash Flow Hedge | Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount	$ 150,000,000		$ 150,000,000	$ 150,000,000
Derivative, maturity date	Jun. 17, 2021
Cash Flow Hedge | Interest Rate Swaps and Caps | Scenario, Forecast
Derivative Instruments Gain Loss [Line Items]
Reclassified out of accumulated other comprehensive income to earnings, amount		$ 111,000

X

- Definition

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

+ References

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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- Definition

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.

+ References

No definition available.

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- Definition

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=64837297&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=64837297&loc=SL5624177-113959

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- Definition

Date the derivative contract matures, in CCYY-MM-DD format.

+ References

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- Definition

Fixed interest rate that will be received or paid upon exercise of the interest rate swaption contract.

+ References

No definition available.

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- Definition

The amount of net gains or losses on interest rate cash flow hedges reclassified during the period to earnings from accumulated other comprehensive income upon the hedged transaction affecting earnings.

+ 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=64837297&loc=SL5624171-113959

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