Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities Gain or Loss Recognized Related to Cash Flow hedges (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative [Line Items]
Amount of income (loss) related to the effective portion recognized in other comprehensive loss		$ (32,351)	$ 15,639	$ (90,997)	$ 12,106
Amount of loss related to the effective portion subsequently reclassified to earnings (1)	[1]	(628)	(628)	(1,255)	(1,255)
Amount of gain (loss) related to the ineffective portion and amount excluded from effectiveness testing		$ 0	$ 0	$ 0	$ 0

[1] Consists of amounts from previous interest rate hedging programs entered into prior to 2015.