Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Stock Options [Member]	Mar. 31, 2012 Stock Options [Member]	Mar. 31, 2013 Convertible Senior Notes Due March 2028 [Member]	Dec. 31, 2012 Convertible Senior Notes Due March 2028 [Member]
Earnings Per Share (Textual) [Abstract]
Number of shares of common stock equivalents related to convertible debt			780,421	1,167
Debt Instrument, Interest Rate, Stated Percentage					3.25%	3.25%
Basic EPS
Net loss available to common stockholders	$ 12,270	$ 3,975
Net Income available to common stockholders, Shares	89,948,000	89,591,000
Net Income available to common stockholders, Per-Share	$ 0.14	$ 0.04
Effect of Dilutive Securities
Equity awards, Income	0	0
Equity awards, Shares	88,000	230,000
Diluted EPS
Net loss available to common stockholders	$ 12,270	$ 3,975
Net income available to common stockholders, shares	90,036,000	89,821,000
Net Income available to common stockholders, Per-Share	$ 0.14	$ 0.04