Derivative Financial Instruments Foreign Currency Exchange Rate Risk (Details)	3 Months Ended				3 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Dec. 03, 2012 Cross-currency swap [Member] USD ($)	Dec. 03, 2012 Cross-currency swap [Member] AUD	Mar. 31, 2014 Cross-currency swap [Member] AUD BBSW Interest Rate [Member]	Mar. 31, 2014 Cross-currency swap [Member] LIBOR Interest Rate [Member]	Mar. 31, 2014 Cross-currency swap [Member] Not Designated as Hedging Instrument [Member] USD ($)	Mar. 31, 2013 Cross-currency swap [Member] Not Designated as Hedging Instrument [Member] USD ($)
Derivatives [Line Items]
Third party debt related to foreign operations denominated in foreign currencies	$ 114,100,000
Notional amount			109,600,000	105,000,000
Derivative, basis spread on variable rate on cross currency derivative					3.25%	2.82%
Description of variable rate basis					Australian dollar Bank Bill Swap Reference Rate (BBSW) plus 3.25%	London Interbank Offered Rate (LIBOR) plus 2.82%
Realized net interest expense/(income) as a result of the quarterly net settlement payments							554,000	814,000
Other non-operating income (expense)	$ 266,000	$ 673,000					$ 176,000	$ (4,000)