Compensation Related Costs, Share Based Payments (Tables)

3 Months Ended

Jun. 30, 2012

Compensation Related Costs, Share Based Payments

Share-based compensation Black-Scholes assumptions

	Three months ended June 30,		Six months ended June 30,
	2012	2011	2012	2011
Risk-free interest rate, average	1.2%	2.5%	1.5%	2.5%
Expected option life, average	7.02 years	6.9 years	7.11 years	6.9 years
Expected price volatility, average	51.7%	52.5%	51.6%	52.5%
Expected dividend yield	0.0%	0.0%	0.0%	0.0%