Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended					3 Months Ended		12 Months Ended	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Mar. 31, 2012 Other liabilities	Dec. 31, 2011 Other liabilities	Mar. 31, 2012 PUERTO RICO	Mar. 31, 2011 PUERTO RICO	Dec. 31, 2010 PUERTO RICO	Mar. 31, 2012 PUERTO RICO Commercial Banking [Member]
Income Taxes [Line Items]
Income Tax Reconciliation Change In Enacted Tax Rate						$ 0	$ 103,287,000
Marginal Income Tax Rate						30.00%		39.00%
Surtax Rate								5.00%
Deferred Tax Assets Net	424,193,000	429,691,000	250,568,000			425,000,000
Deferred Tax Liabilities	284,582,000	279,469,000		24,000,000	25,000,000
Income Tax Examination Minimum Likelihood Of Tax Benefits Being Realized Upon Ultimate Settlement	50.00%
Deferred Tax Assets Valuation Allowance	1,260,099,000	1,259,358,000
Unrecognized Tax Benefits Interest On Income Taxes Accrued	6,000,000		6,600,000
Income Tax Examination Penalties Accrued	0		0
Unrecognized Tax Benefits That Would Impact Effective Tax Rate	25,300,000		30,000,000
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit	11,000,000
Adjusted Marginal Income Tax Rate								40.95%
Deferred Tax Assets Tax Credit Carryforwards Other	$ 3,139,000	$ 3,459,000
Effective Income Tax Rate Continuing Operations						25.00%	93.00%		20.00%