Activity in Allowance for Losses for Non-Covered Loans (Detail) (USD $) In Thousands, unless otherwise specified			9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Non-Covered Loans	Sep. 30, 2011 Non-Covered Loans	Sep. 30, 2012 Mortgage Receivable Non-Covered Loans	Sep. 30, 2011 Mortgage Receivable Non-Covered Loans	Sep. 30, 2012 Other loan Non-Covered Loans	Sep. 30, 2011 Other loan Non-Covered Loans
Valuation Allowance [Line Items]
Balance, beginning of period	$ 139,015	$ 137,290	$ 137,290	$ 158,942	$ 121,995	$ 140,834	$ 15,295	$ 18,108
Charge-offs			(41,759)	(83,479)	(35,542)	(73,994)	(6,217)	(9,485)
Recoveries			3,484	4,916	735	2,189	2,749	2,727
Provision for (recovery of ) loan losses			40,000	59,000	38,506	53,287	1,494	5,713
Balance, end of period	$ 139,015	$ 137,290	$ 139,015	$ 139,379	$ 125,694	$ 122,316	$ 13,321	$ 17,063