Fair Value (Details 2) (Interest Rate Contract Assets And Liabilities Net [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Interest Rate Contract Assets And Liabilities Net [Member]
Assets (Liabilities):
Balance at the beginning of the period	$ 18,535	$ 43,680	$ 63,471	$ 25,783
Total gains or losses (realized/unrealized):
Included in earnings (or changes in net assets)	(5,425)	(149)	(50,361)	17,748
Balance at the end of the period	$ 13,110	$ 43,531	$ 13,110	$ 43,531