Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities (Details 2) (Foreign Exchange Forward [Member], Designated as Hedging Instrument [Member]) In Millions, unless otherwise specified	Sep. 30, 2013 Foreign Exchange Forward Contract, USD To GBP Exchange, Various Due September 2013 to December 2013 [Member] USD ($)	Sep. 30, 2013 Foreign Exchange Forward Contract, USD To GBP Exchange, Various Due January 2014 to December 2014 [Member] USD ($)	Sep. 30, 2013 Foreign Exchange Forward Contract, Euro To GBP Exchange, Various Due October 2013 to December 2013 [Member] EUR (€)	Jun. 30, 2013 Foreign Exchange Forward Contract, Euro To GBP Dollar Exchange, Various Due January 2014 to December 2014 [Member] EUR (€)
Derivative [Line Items]
Notional amount of foreign currency derivatives	$ 0.50	$ 1.80	€ 0.12	€ 0.48
Derivative, average foreign currency option strike price	1.58	1.57	1.24	1.16