Insurance Activity - Summary of Losses and Loss Adjustment Reserve Activity (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Insurance [Abstract]
Balance at beginning of period	$ 82,524	$ 142,119
Incurred (recovered) - prior periods	(1,918)	30,111
Paid - prior periods	(23,036)	(89,706)
Total	$ 57,570	$ 82,524