Loans in non-performing status and accruing loans past-due 90 days or more by loan class (Parenthetical) (Detail) - Entity [Domain] - Internal Credit Assessment [Domain] - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-for-sale		$ 202,287	$ 106,104
Loans held-in-portfolio, net of unearned income	[1]	22,435,145	19,404,451
Financing Receivable Recorded Investment Nonaccrual Status		50,875	18,899
Reverse Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable Recorded Investment 90 Days Past Due And Still Accruing		72,000	66,000
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		133,000	125,000
Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-for-sale		151,637	100,166
Loans held-in-portfolio, net of unearned income		7,225,823	6,502,886
Financing Receivable Recorded Investment Nonaccrual Status		225	14,041
Mortgages [Member] | SOP Other Loans Acquired [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held-in-portfolio, net of unearned income		$ 269,000	$ 59,000

[1] Non-covered loans held-in-portfolio at June 30, 2015 are net of $100 million in unearned income and exclude $202 million in loans held-for-sale. (December 31, 2014 - $94 million in unearned income and $106 million in loans held-for-sale.)