Capital and Financing Transactions - Tabular Disclosure of the Effect of Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Debt Disclosure [Abstract]
Amount of gain (loss) recognized in other comprehensive income (loss) on derivatives	$ (2,341)	$ 680	$ (8,017)	$ (4,425)
Net loss reclassified from accumulated other comprehensive income (loss) into earnings	1,353	1,734	2,716	3,592
Amount of loss recognized in income on derivatives (ineffective portion, reclassifications of missed forecasted transactions and amounts excluded from effectiveness testing)	$ 11	$ 1,221	$ 37	$ 1,245