Financial Instruments (Proceeds) (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financial Instruments Proceeds Details 4
Proceeds from sales and maturities	$ 107,871	$ 119,507	$ 86,668
Realized gains	4	4	0
Realized losses	$ 0	$ 0	$ 0