Shareholders’ equity (Tables)

9 Months Ended

Sep. 30, 2012

Stockholders' Equity Note [Abstract]

Schedule of Stockholders Equity

The rights, preferences and privileges of holders of our common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of our preferred stock which are currently outstanding, including our Series A Convertible Preferred Stock, or any series which we may designate and issue in the future.

Common and Preferred Stock Activity:	Preferred stock		Common stock
	Series A convertible		Treasury	Outstanding
Beginning balance as of December 31, 2011	80,718		4,386,521	88,844,327
Repurchase of common stock	—		400,000	(400,000	)
Conversion of convertible preferred stock	(176	)	—	17,587
Issuance for stock compensation plans	—		—	24,531
Ending balance as of September 30, 2012	80,542		4,786,521	88,486,445