Income Taxes - Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Losses on loans and other assets	$ 309,523	$ 322,818	$ 345,609
Operating lease liabilities	128,178
Retirement benefits	55,048	30,057	45,322
Postretirement and other employee benefits	24,023	23,563	26,009
Incentive and other compensation plans	26,861	24,796	25,050
Interest on loans			37,900
Stock-based compensation	27,912	26,759	26,676
Unrealized losses		52,580
Losses on cash flow hedges		1,861	4,033
Other	69,863	43,880	66,247
Gross deferred tax assets	641,408	526,314	576,846
Right of use assets and other leasing transactions	(326,626)	(186,787)	(181,159)
Unrealized gains	(13,322)		(94,285)
Capitalized servicing rights	(56,649)	(54,894)	(51,781)
Depreciation and amortization	(66,925)	(61,881)	(52,733)
Interest on loans	(23,552)	(18,920)
Gains on cash flow hedges	(36,845)
Other	(40,472)	(30,211)	(25,632)
Gross deferred tax liabilities	(564,391)	(352,693)	(405,590)
Net deferred tax asset	$ 77,017	$ 173,621	$ 171,256