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

+ Details

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- Definition

Average fixed interest rate related to the group of interest rate derivatives.

+ References

No definition available.

+ Details

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- Definition

Average remaining period until maturity of the derivative contract, 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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- Definition

High end period remaining until maturity for the derivative contract, 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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- Definition

Low end period remaining until maturity of derivative contract, 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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- Details

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- Details

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Hedging Exposure Future Cash Flows with Interest Rate Swaps For Forecasted Transactions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments Gain Loss [Line Items]
Weighted Average Fixed Interest Rate in Contract	1.28%
Weighted Average Remaining Term in Months	16 months
Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Notional Amount	8,300,000	$ 10,500,000	$ 10,700,000
12 Months or Less
Derivative Instruments Gain Loss [Line Items]
Weighted Average Fixed Interest Rate in Contract	1.73%
Weighted Average Remaining Term in Months	6 months
Maturity - lower remaining maturity range	0 months
Maturity - higher remaining maturity range	12 months
12 Months or Less \| Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Notional Amount	3,700,000
Over 12 Months to 24 Months
Derivative Instruments Gain Loss [Line Items]
Weighted Average Fixed Interest Rate in Contract	0.92%
Weighted Average Remaining Term in Months	18 months
Maturity - lower remaining maturity range	12 months
Maturity - higher remaining maturity range	24 months
Over 12 Months to 24 Months \| Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Notional Amount	2,400,000
Over 24 Months to 36 Months
Derivative Instruments Gain Loss [Line Items]
Weighted Average Fixed Interest Rate in Contract	0.89%
Weighted Average Remaining Term in Months	29 months
Maturity - lower remaining maturity range	24 months
Maturity - higher remaining maturity range	36 months
Over 24 Months to 36 Months \| Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Notional Amount	1,800,000
Over 36 Months to 48 Months
Derivative Instruments Gain Loss [Line Items]
Weighted Average Fixed Interest Rate in Contract	0.96%
Weighted Average Remaining Term in Months	38 months
Maturity - lower remaining maturity range	36 months
Maturity - higher remaining maturity range	48 months
Over 36 Months to 48 Months \| Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Notional Amount	400,000