Fresh Start Accounting - Adjustment Reflects Reduction of Equity Value Resulting from Fresh Start Accounting (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 19, 2012
Fresh-Start Adjustment [Line Items]
Fair market value reduction	$ 8,400
Elimination of Court assigned value related to NOLs	70,000
Total change in fair market value affecting Equity Value	78,400
Court assigned Equity Value recorded as additional paid-in capital	154,998
Total change in fair market value affecting Equity Value	78,400
Additional paid-in capital at March 19, 2012	76,598
WMMRC [Member]
Fresh-Start Adjustment [Line Items]
Fair market value of WMMRC (Court assigned)	140,000
Fair market value of WMMRC	131,600
Fair market value reduction	$ 8,400

Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.30(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AdditionalPaidInCapital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant