Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Basic EPS
Net loss available to common stockholders	$ 22,973	$ 38,611	$ 26,948	$ 51,075
Net Income available to common stockholders, Shares	89,631,000	89,310,000	89,611,000	89,299,000
Net Income available to common stockholders, Per-Share	$ 0.26	$ 0.43	$ 0.30	$ 0.57
Effect of Dilutive Securities
Equity awards, Income	0	0	0	0
Equity awards, Shares	102,000	402,000	166,000	384,000
Diluted EPS
Net loss available to common stockholders	$ 22,973	$ 38,611	$ 26,948	$ 51,075
Net income available to common stockholders, shares	89,733,000	89,712,000	89,777,000	89,683,000
Net Income available to common stockholders, Per-Share	$ 0.26	$ 0.43	$ 0.30	$ 0.57
Stock Options [Member]
Earnings Per Share (Textual) [Abstract]
Number of shares of common stock equivalents related to convertible debt	632,213	1,056,901		1,419,282
Convertible Senior Notes Due March 2028 [Member]
Earnings Per Share (Textual) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.25%		3.25%