Schedule of Interest Rate Swap Agreements on Accumulated Other Comprehensive Income (Details) - Interest Rate Swap - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Beginning balance	$ 673	$ (30,042)
Reclassification of net losses to the income statement	1,376	13,438
Ending balance	$ 2,049	$ (16,604)