Derivative Instruments and Hedging Activities- Effects on Statements of Income (Loss) and Consolidated Statements of Comprehensive Loss (Details) - USD ($) $ in Thousands  | 
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2016  | 
Jun. 30, 2015  | 
Jun. 30, 2016  | 
Jun. 30, 2015  | 
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| Derivatives Designated as Hedging Instruments | Interest rate swap instruments | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Amount of Gain Recognized in Net Income | $ 83 | $ 101 | $ 153 | $ (184) | 
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- Definition 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. No definition available. 
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- Definition Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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