Significant Accounting Policies, Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Significant Accounting Policies [Abstract]
Options excluded from the computation of diluted loss per share (in shares)		693,000
Weighted average stock options excluded from computation of diluted loss per share (in shares)	2,600,000	3,400,000
Earnings (loss) per share:
Net income (loss)	$ 1,882	$ (4,373)
Basic [Abstract]
Weighted-average shares of common stock outstanding (in shares)	50,085,000	48,418,000
Shares used in computing basic earnings (loss) per share (in shares)	50,085,000	48,418,000
Basic earnings (loss) per share (in dollars per share)	$ 0.04	$ (0.09)
Diluted [Abstract]
Weighted-average shares of common stock outstanding (in shares)	50,085,000	48,418,000
Add: Common equivalent shares outstanding (in shares)	2,056,000	0
Shares used in computing diluted earnings (loss) per share (in shares)	52,141,000	48,418,000
Diluted earnings (loss) per share (in dollars per share)	$ 0.04	$ (0.09)