Loans in non-performing status and accruing loans past-due 90 days or more by loan class (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-for-sale	$ 94,877		$ 110,426
Loans held-in-portfolio, net of unearned income	21,611,777	[1]	21,611,866	[1]
Reverse Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-in-portfolio, net of unearned income	52,000		50,000
Residential Mortgage Loans Insured By FHA [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable Recorded Investment 90 Days Past Due And Still Accruing	117,000		115,000
Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-for-sale	94,877		109,823
Loans held-in-portfolio, net of unearned income	6,669,376		6,681,476
Mortgages [Member] | SOP Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-in-portfolio, net of unearned income	49,000		43,000
Nonperforming Financing Receivable Member
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-for-sale	$ 789		$ 1

[1] Non-covered loans held-in-portfolio at March 31, 2014 are net of $91 million in unearned income and exclude $95 million in loans held-for-sale. (December 31, 2013 - $92 million in unearned income and $110 million in loans held-for-sale.)