Net Income (Loss) Per Share (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Weighted average number of common shares outstanding:
Weighted average number of shares of common stock outstanding basic	58,880,000	57,815,000	58,723,000	57,671,000
Dilutive common stock equivalents relating to options and restricted stock	1,510,000	1,733,000	1,171,000
Weighted average number of shares of common stock outstanding - diluted	60,390,000	59,548,000	59,894,000	57,671,000