Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Stock Options [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2013 Stock Options [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2013 Convertible Senior Notes Due March 2028 [Member]	Dec. 31, 2012 Convertible Senior Notes Due March 2028 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted Average Number of Shares Outstanding, Basic	100,778,000	89,429,000	96,893,000	89,550,000
Earnings Per Share (Textual) [Abstract]
Number of shares of common stock equivalents related to convertible debt		772,368	1,142,530	640,660	1,202,100	632,213	1,202,100	632,213
Debt Instrument, Interest Rate, Stated Percentage									3.25%	3.25%
Earnings Per Share, Diluted	$ (0.46)	$ (0.18)	$ (0.71)	$ 0.12
Incremental Common Shares Attributable to Share-based Payment Arrangements	0		0	140,000
Basic EPS
Net loss available to common stockholders	$ (46,265)	$ (15,821)	$ (69,035)	$ 11,127
Net Income available to common stockholders, Per-Share	$ (0.46)	$ (0.18)	$ (0.71)	$ 0.12
Diluted EPS
Net loss available to common stockholders	$ (46,265)	$ (15,821)	$ (69,035)	$ 11,127
Net Income available to common stockholders, Per-Share	100,778,000	89,429,000	96,893,000	89,690,000