Derivatives (Gains and Losses on Derivatives that were Not Designated as Hedging Instruments) (Details)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 Other Income (Expense) [Member] Currency contracts [Member] USD ($)	Sep. 30, 2012 Other Income (Expense) [Member] Currency contracts [Member] USD ($)	Sep. 30, 2013 Other Income (Expense) [Member] Currency contracts [Member] USD ($)	Sep. 30, 2012 Other Income (Expense) [Member] Currency contracts [Member] USD ($)	Sep. 30, 2013 Not Designated as Hedging Instrument [Member] Currency contracts [Member] CAD	Dec. 31, 2012 Not Designated as Hedging Instrument [Member] Currency contracts [Member] CAD
Derivative [Line Items]
Derivative, notional amount									4,300,000	14,800,000
Gain (loss) on derivatives not designated as hedging instruments	$ (273,000)	$ (190,000)	$ 144,000	$ (220,000)	$ (273,000)	$ (190,000)	$ 144,000	$ (220,000)