XML 16 R46.htm IDEA: XBRL DOCUMENT

Stock-Based Compensation (Summary of Assumptions) (Detail) (Performance Share Unit Awards [Member])	9 Months Ended
	Sep. 30, 2012
Performance Share Unit Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forecast period (years)	4 years 2 days
Risk-free rate	0.46%
Oasis volatility	51.00%

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References+ Details