Non-operating (loss) income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Non-operating (loss) income, net [Abstract]
Unrealized Gain (Loss) on Derivatives	$ (4,747)	$ (6,562)	$ (9,058)	$ 3,953
Interest and Dividend Income, Securities	639	197	1,271	708
Other Nonoperating Income (Expense)	133	(108)	1,458	376
Nonoperating (loss) Income	$ (3,975)	$ (6,473)	$ (6,329)	$ 5,037