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 $ 147 $ 2,523 $ 808
Net deferred losses on cash flow hedges for the period (4,519) (622) 1,607
Amount reclassified into current period earnings (329) (1,754) 108
Ending Balance $ (4,701) $ 147 $ 2,523