Derivative Instruments -Additional information about the financial statement effects related to our cash flow hedges (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2014
Effects of derivative instruments
AOCI related to a previously held derivative instrument designated as a cash flow hedge		$ 100,000	$ 100,000
Amount of interest expense reduction from ineffective derivative instrument	$ 0	100,000
Cash Flow Hedging \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Effects of derivative instruments
Amount of Gain Recognized in OCI on Derivatives (Effective Portion)		122,000	371,000
Cash Flow Hedging \| Interest expense Member \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Effects of derivative instruments
Amount of Gain Recognized in OCI on Derivatives (Effective Portion)		$ 122,000	$ 371,000

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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

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=56946850&loc=SL5624171-113959

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- Definition

Accumulated Other Comprehensive Income Related To Previously Held Derivative Instrument Designated As Cash Flow Hedge

+ References

No definition available.

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- Definition

Represents the interest expense reduction reclassified to income on derivative instruments ineffective portion.

+ References

No definition available.

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