Fresh Start Financial Statement Reporting - Schedule of Reconciliation of Enterprise Value to Reorganization Value, and Determination of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2013
Reorganizations [Abstract]
Enterprise value	$ 185,000
Add: Fair value of liabilities	28,393,020
Add: Fair value of noncontrolling interest	275,415
Total assets	28,853,435
Less: Fair value of identified tangible and intangible assets	28,338,924
Reorganization value in excess of fair value of assets (goodwill)	$ 514,511