Derivatives and Hedging Activities (Details Textuals)		3 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2013 Realized within twelve months [Member] USD ($)	Mar. 31, 2013 Realized within twelve months [Member] JPY (¥)
Derivatives and Hedging Activities
Forward contracts cash flow hedge for future purchases of currency		$ 131,000,000	¥ 12,300,000,000
Unrealized Gain (Loss) on Foreign Currency Derivatives, Net, before Tax		(12,900,000)
Foreign currency forward contracts outstanding to buy dollar		196,100,000
Foreign currency forward contracts outstanding to sell dollar		101,700,000
Cash Flow Hedge
Minimum liquidity	1,000,000,000
Notional amount of currency swap transactions	$ 30,800,000