Sales Activity of Series D Preferred Shares (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013	Dec. 31, 2012
Temporary Equity [Line Items]
Aggregate purchase price	$ 65,000
Initial value of warrants and investor SARs issued to-date	(9,751)
Costs incurred	(4,952)
Total discount	(14,703)
Discount amortization to-date	985
Carrying amount of Series D Preferred Shares	$ 51,282	$ 52,278

Carrying amount, attributable to parent, of an entity's issued and outstanding stock which is not included within permanent equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. Includes stock with a put option held by an ESOP and stock redeemable by a holder only in the event of a change in control of the issuer.

No definition available.

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