| **Derivative Financial Instruments - Fair Value of Derivative Financial Instruments and Their Classification on Balance Sheet (Details) (Interest rate contracts, USD $)In Thousands, unless otherwise specified** | Sep. 30, 2013 | Dec. 31, 2012 |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| Designated as Hedging Instrument | Other Assets                                                                                                                                                                    |          |          |
| **Derivatives, Fair Value [Line Items]**                                                                                                                                                                           |          |          |
| Asset Derivatives                                                                                                                                                                                                  | $ 421         | $ 197         |
| Designated as Hedging Instrument | Other Liabilities                                                                                                                                                               |          |          |
| **Derivatives, Fair Value [Line Items]**                                                                                                                                                                           |          |          |
| Liability derivatives                                                                                                                                                                                              | 1,441         | 3,332         |
| Not Designated as Hedging Instrument | Other Assets                                                                                                                                                                |          |          |
| **Derivatives, Fair Value [Line Items]**                                                                                                                                                                           |          |          |
| Asset Derivatives                                                                                                                                                                                                  | 3,054         | 6,103         |
| Not Designated as Hedging Instrument | Other Liabilities                                                                                                                                                           |          |          |
| **Derivatives, Fair Value [Line Items]**                                                                                                                                                                           |          |          |
| Liability derivatives                                                                                                                                                                                              | $ 3,136       | $ 6,434       |

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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value before effects of master netting arrangements, of a financial asset or other 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.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=28370219&loc=SL20226000-175313Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=20225523&loc=SL20225862-175312Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
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.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=28370219&loc=SL20226000-175313Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=20225523&loc=SL20225862-175312Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959
+ Details**Name:**us-gaap_DerivativeFairValueOfDerivativeLiability**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                 |
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| - Details**Name:**us-gaap_DerivativesFairValueLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |