Derivative Financial Instruments (Details 1) (Interest Rate Contracts One [Member], Derivative in cash flow hedging relationship [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Interest Rate Contracts One [Member] \| Derivative in cash flow hedging relationship [Member]
Effect of the derivative instruments on the consolidated statement of income Derivative in cash flow hedging relationship
Amount of Loss Recognized in Other Comprehensive Income on Derivative (Effective Portion)	$ 1,028	$ (785)	$ 1,313	$ (419)

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration