v3.5.0.2

Derivative Instruments - Summary of Interest Rate Swap Positions (Detail)	9 Months Ended
	Sep. 30, 2016 USD ($)
Minimum [Member]
LIBOR-Based Debt:
Margin on variable-rate debt	0.30%
Maximum [Member]
LIBOR-Based Debt:
Margin on variable-rate debt	2.00%
U.S. Dollar-denominated interest rate swap 1 [Member]
LIBOR-Based Debt:
U.S. Dollar-denominated interest rate swap, Notional Amount	$ 200,000,000
U.S. Dollar-denominated interest rate swap, Fair Value / Carrying Amount of Asset (Liability)	$ (28,000)
U.S. Dollar-denominated interest rate swap, Remaining Term (years)	0 years
U.S. Dollar-denominated interest rate swap, Fixed Interest Rate	2.61%
U.S. Dollar-denominated interest rate swap 2 [Member]
LIBOR-Based Debt:
U.S. Dollar-denominated interest rate swap, Notional Amount	$ 200,000,000
U.S. Dollar-denominated interest rate swap, Fair Value / Carrying Amount of Asset (Liability)	$ (1,828,000)
U.S. Dollar-denominated interest rate swap, Remaining Term (years)	4 years 2 months 12 days
U.S. Dollar-denominated interest rate swap, Fixed Interest Rate	1.46%
U.S. Dollar-denominated interest rate swap 3 [Member]
LIBOR-Based Debt:
U.S. Dollar-denominated interest rate swap, Notional Amount	$ 150,000,000
U.S. Dollar-denominated interest rate swap, Fair Value / Carrying Amount of Asset (Liability)	$ (2,699,000)
U.S. Dollar-denominated interest rate swap, Remaining Term (years)	4 years 3 months 18 days
U.S. Dollar-denominated interest rate swap, Fixed Interest Rate	1.55%
U.S. Dollar-denominated interest rate swap 4 [Member]
LIBOR-Based Debt:
U.S. Dollar-denominated interest rate swap, Notional Amount	$ 50,000,000
U.S. Dollar-denominated interest rate swap, Fair Value / Carrying Amount of Asset (Liability)	$ (69,000)
U.S. Dollar-denominated interest rate swap, Remaining Term (years)	4 years 3 months 18 days
U.S. Dollar-denominated interest rate swap, Fixed Interest Rate	1.16%

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

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13495-108611

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

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Namespace Prefix:
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X

- Details

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X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

X

- Details

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