Fair Value Measurements and Derivatives - Amounts Recognized Within Assets and Liabilities Based on Right of Offset (Details 1) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Gross Amounts, Assets	$ 70,316	$ 3,446
Gross Amounts Offset, Assets	(3,252)	(1,370)
Total Net Amounts, Assets	67,064	2,076
Gross Amounts Not Offset, Assets	(49,147)	(2,043)
Total Net Amounts, Assets	17,917	33
Gross Amounts, Liabilities	294,485	344,619
Gross Amounts Offset, Liabilities	(2,638)	(551)
Total Net Amounts, Liabilities	291,847	344,068
Gross Amounts Not Offset, Liabilities	(39,761)	(336,645)
Total Net Amounts, Liabilities	$ 252,086	$ 7,423