Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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+ Details

Loss per Common Share - Additional Information (Detail)	12 Months Ended
Loss per Common Share - Additional Information (Detail)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock Options
Earnings Per Share Disclosure [Line Items]
Antidilutive securities excluded from computation of earnings per share	27,844,000	30,676,000	30,267,000
Preferred Stock
Earnings Per Share Disclosure [Line Items]
Antidilutive securities excluded from computation of earnings per share	15,124,000	19,858,000	19,858,000
Convertible Senior Notes
Earnings Per Share Disclosure [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,100,000