Derivative Instruments and Hedging Activities (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Debt Instrument [Line Items]
Amount of gain (loss) related to the effective portion recognized in other comprehensive income (loss)	$ (3,533,000)	$ 0
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Number of interest rate swap agreements entered into (swap contracts)	5
Maximum period of hedging exposure to the variability in future cash flows for forecasted transactions (in years)	10
Derivative, Net Liability Position, Aggregate Fair Value	3,500,000
Assets Needed for Immediate Settlement, Aggregate Fair Value	3,500,000
Average Fixed Interest Rate	2.492%
Notional Amount	250,000,000
Amount of gain (loss) related to the effective portion recognized in other comprehensive income (loss)	$ (3,500,000)
Time period when the effects of the swaps may be reclassified into earnings (in months)	12

Maximum period of hedging exposure to the variability in future cash flows for forecasted transactions (in years)

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- Definition

Number of interest rate swap agreements entered into

+ References

No definition available.

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- Definition

Time period when the effects of the swaps may be reclassified into earnings (in months)

+ References

No definition available.

+ Details

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

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

The aggregate fair value of assets needed to immediately settle the derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4H

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624258-113959

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- 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

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

The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4H

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624258-113959

+ Details

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- Details

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