Derivative Instruments and Hedging Activities-Interest Rate Swaps (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Derivative [Line Items]
Amount of loss (gain) recognized in OCI on derivative	$ (272)	$ 1,012	$ 986	$ 2,535
Amount of loss reclassified from accumulated OCI into income			893	$ 1,304
Accrued expenses and accounts payable
Derivative [Line Items]
Interest rate derivative at fair value	646		$ 646		$ 553
Cash Flow Hedging | Interest Expense | Interest Rate Swap
Derivative [Line Items]
Amount of loss reclassified from accumulated OCI into income	$ 279	$ 434