| Derivative Instruments and Hedging Activities (Tables) | 3 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Mar. 31, 2017 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Derivative Instruments And Hedging Activities Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Gains (Losses) Relating to Derivative Instruments Recorded in Other Comprehensive Income (loss) | The following table summarizes gains (losses) relating to derivative instruments recorded in other comprehensive income (loss) during the three months ended March 31, 2017 and 2016: 
 
 
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| Gains (Losses) Relating to Derivative Instruments Recorded to Income | The following table summarizes gains (losses) relating to derivative instruments recorded to income during the three months ended March 31, 2017 and 2016: 
 
 
 
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| Gains (Losses) Relating to Derivative Instruments Reclassified from Accumulated Other Comprehensive Loss into Income Effective Portion | The following table summarizes gains (losses) relating to derivative instruments reclassified from accumulated other comprehensive loss into income during the three months ended March 31, 2017 and 2016: 
 
 
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