Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2013

Earnings Per Share

Schedule of information required to compute basic and diluted earnings per share

	Three Months Ended March 31,
	2012	2013
Basic and diluted:
Weighted-average number of common shares outstanding	85,677,090	93,132,454

Schedule of potentially dilutive securities that have been excluded from the diluted net loss per share calculations because their effect would have been antidilutive

	March 31,
	2012	2013
Options	10,903,234	11,994,610
Warrants	2,130,682	2,130,682
Convertible notes	13,164,557	15,995,781
Restricted Stock Units	1,420,000	1,545,000