STOCK-BASED COMPENSATION - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense related to our stock-based awards	$ 5	$ 5
Employee Restricted Equity Awards
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share based compensation granted	719,566
Assumed average forfeiture rate	12.00%
Vesting rights	The terms of the restricted stock awards include vesting provisions based solely on continued service. If the service criteria are satisfied, the restricted stock awards vest during March of 2013, 2014, and 2015.
Restricted stock units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share based compensation granted	108,164
Restricted stock units | Vesting of RSUs will not occur until at least three years have passed following an acquisition
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Vesting of RSUs	3 years
Restricted stock units | Upon the later of three years from the grant date
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Vesting of RSUs	3 years
Restricted stock units | One year following the commencement of commercial operations for development projects
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Vesting of RSUs	1 year