Summary of Losses and Loss Adjustment Reserve Activity (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012 Successor [Member]	Dec. 31, 2011 Predecessor [Member]
Balance at beginning of period	$ 142,119	$ 190,036
Incurred-prior periods	27,567	47,321
Paid-prior periods	(38,997)	(95,238)
Losses and loss adjustment reserves	$ 130,689	$ 142,119	[1]

[1] The Balance Sheet at December 31, 2011 is derived from the audited financial statements of the Predecessor.