v2.4.0.8
Derivative Instruments and Hedging Activities - Additional Information (Details) (USD $)
9 Months Ended 12 Months Ended
Sep. 30, 2013
Dec. 31, 2011
Dec. 31, 2012
Derivative Instruments and Hedging Activities Disclosure [Abstract]      
Cash flow hedge loss included in accumulated other comprehensive income (loss) to be reclassified to earnings within 12 months $ (3,800,000)    
Fair market value of interest rate swaps, current liability 15,403,000   705,000
Fair market value of interest rate swaps, noncurrent liability 9,568,000 10,600,000 14,938,000
Loss from hedge ineffectiveness   200,000  
Net loss included in accumulated other comprehensive income (loss) to be reclassified into interest expense within the next 12 months     $ 4,100,000