Convertible Senior Notes (Warrants) (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended
	Jun. 30, 2012 USD ($) $ / shares shares
Debt Instrument [Line Items]
Shares exercisable upon conversion	9.8
2017 Warrants [Member]
Debt Instrument [Line Items]
Proceeds from sale of warrants | $	$ 38.4
Shares exercisable upon conversion	9.8
Exercise price of warrants (in dollars per share) | $ / shares	$ 34.20