Debt (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended			0 Months Ended	3 Months Ended
	Mar. 31, 2013 April 2011 Line of Credit as Amended October 2012 [Member]	Jun. 30, 2013 Senior Exchangeable Notes due 2015 at a fixed interest rate of 4.50% [Member]	Mar. 31, 2013 Senior Exchangeable Notes due 2015 at a fixed interest rate of 4.50% [Member]	Apr. 02, 2013 Warrants on Senior Exchangeable Notes due 2012 [Member]	Mar. 31, 2013 Warrants on Senior Exchangeable Notes due 2012 [Member] unit
Debt Instrument [Line Items]
Beginning Date for Maturity of Warrants					Jan. 15, 2013
Ending Date for Maturity of Warrants					Mar. 27, 2013
Number of Warrants Settled					7,984,078
Total Number of Warrants					8,313,511
Shares issued on conversion of warrants				97,918	2,036,976
Ending Date for Settlement of Warrants				Apr. 02, 2013
Debt Instrument, Face Amount			$ 172.5
Debt Instrument, Interest Rate, Stated Percentage			4.50%
Debt Instrument, Maturity Date, Description			2015
Debt Instrument, Exchange Feature, Exchange Period, Beginning Date		Mar. 31, 2013	Dec. 31, 2012
Debt Instrument, Exchange Feature, Exchange Period, End Date		Jun. 30, 2013	Mar. 31, 2013
Debt Instrument, Exchange Feature, Description			Per the indenture, in order for the notes to become exchangeable, the Company's stock price must exceed 130 percent of the exchange price for 20 trading days during a period of 30 consecutive trading days as of the last day of the quarter.
Line of Credit Facility, Increase (Decrease) for Period, Net	(70)
Line of Credit Facility, Maximum Borrowing Capacity	450
Line of Credit Facility, Remaining Borrowing Capacity	$ 242