Derivative Instruments (Current Period Cash Flow Hedges in AOCI (loss) before Taxes) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments
Beginning Balance	$ (3,068)	$ (962)	$ (2,462)
Net deferred losses on cash flow hedges for the period	(680)	(2,207)	1,415
Amount reclassified into current period earnings	95	101	85
Ending Balance	$ (3,653)	$ (3,068)	$ (962)