Summary of Debt, Net of Discounts (Parenthetical) (Detail) (Revolving Credit Facilities, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Debt Instrument [Line Items]
Principal amount	$ 89,600	[1]
Collateralized Debt Obligations
Debt Instrument [Line Items]
Principal amount	$ 42,000
expiration date	20112-06

[1] Our $42 million collateralized revolving credit facility expired in June 2012.