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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- Definition

The premium (cost) of a hedge, net of any cash received on settlement during the period.

+ References

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- Definition

Fixed interest rate related to the interest rate derivative.

+ 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=84234895&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=84234895&loc=SL5624177-113959

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- Definition

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.

+ References

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- Definition

The net gain (loss) during the reporting period due to ineffectiveness in interest rate cash flow hedges. Recognized in earnings.

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- Definition

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

Reference 1: 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=77997519&loc=d3e13433-108611

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- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959

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Derivative Financial Instruments - Cash Flow Hedges (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) derivative	Dec. 31, 2016 USD ($) derivative	Dec. 31, 2015 USD ($)
Cash Flow Hedges
Effect of cash flow hedging relationships
Pretax gains recognized in other comprehensive income on derivatives (effective portion)	$ 2,473	$ 2,397	$ 1,684
Pretax gain reclassified from accumulated other comprehensive income			(387)
Interest rate swaps
Cash flow hedges
Recognized expenses related to the ineffective portion	100	300	100
Interest rate swaps \| Cash Flow Hedges
Cash flow hedges
Net interest expense on derivative	$ 2,400	$ 3,200	$ 3,900
Minimum \| Interest rate swaps \| Cash Flow Hedges
Cash flow hedges
Fixed interest rate (as a percent)	2.98%	2.98%
Maximum \| Interest rate swaps \| Cash Flow Hedges
Cash flow hedges
Fixed interest rate (as a percent)	3.03%	3.03%
Derivatives designated as hedging instruments \| Interest rate swaps
Cash flow hedges
Notional amounts	$ 194,687	$ 200,504
Derivatives designated as hedging instruments \| Interest rate swaps \| Cash Flow Hedges
Cash flow hedges
Number of derivatives carried \| derivative	2	2
Notional amounts	$ 150,000	$ 150,000
Fair value losses	$ 1,500	$ 3,800