Derivatives and Hedging Activities (Details Textuals)		6 Months Ended
	Jun. 30, 2013 USD ($)	Jun. 30, 2013 Realized within twelve months [Member] USD ($)	Jun. 30, 2013 Realized within twelve months [Member] JPY (¥)
Derivatives and Hedging Activities
Forward contracts cash flow hedge for future purchases of currency		$ 247,000,000	¥ 24,500,000,000
Unrealized Gain (Loss) on Foreign Currency Derivatives, Net, before Tax		(7,400,000)
Foreign currency forward contracts outstanding to buy dollar		107,900,000
Foreign currency forward contracts outstanding to sell dollar		(72,500,000)
Cash Flow Hedge
Minimum liquidity	1,000,000,000
Notional amount of currency swap transactions	$ 29,300,000