Condensed Balance Sheet - Parent Company Only (Detail) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments in subsidiaries:
Goodwill		$ 2,416	$ 2,416	$ 2,416
Other assets	[1]	7,999	8,241
Total Assets		141,082	138,706	130,443
Liabilities
Other short-term borrowings		1,507	1,556
Accrued expenses and other liabilities	[1]	2,341	2,642
Long-term debt (external)	[1]	15,844	14,967
Total liabilities		125,212	123,041
Shareholders' Equity
Common stock	[2]	2,051	2,051
Preferred stock	[3]	1,331	1,331
Capital surplus		2,666	2,646
Retained earnings		12,358	11,141
Accumulated other comprehensive income		197	429	$ 82	$ 375
Treasury stock	[2]	(2,764)	(1,972)
Noncontrolling interests		31	39
Total Equity		15,839	15,626
Total Liabilities and Equity		141,082	138,706
Parent Company Only
Assets
Cash		128
Short-term Investments		3,728	3,189
Loans to subsidiaries:
Nonbank subsidiaries		982	984
Total loans to subsidiaries		982	984
Investments in subsidiaries:
Nonbank subsidiaries		17,831	17,186
Total investment in subsidiaries		17,831	17,186
Goodwill		80	80
Other assets		432	451
Total Assets		23,181	21,890
Liabilities
Other short-term borrowings		404	426
Accrued expenses and other liabilities		433	405
Long-term debt (external)		6,474	5,394
Total liabilities		7,311	6,225
Shareholders' Equity
Common stock		2,051	2,051
Preferred stock		1,331	1,331
Capital surplus		2,666	2,646
Retained earnings		12,358	11,141
Accumulated other comprehensive income		197	429
Treasury stock		(2,764)	(1,972)
Noncontrolling interests		31	39
Total Equity		15,870	15,665
Total Liabilities and Equity		$ 23,181	$ 21,890

[1] Includes $152 and $179 of cash and due from banks, $2,537 and $3,378 of portfolio loans and leases, $(28) and $(22) of ALLL, $20 and $25 of other assets, $3 and $5 of other liabilities and $2,493 and $3,434 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2015 and 2014, respectively. For further information, refer to Note 11.

[2] Common shares: Stated value $2.22 per share; authorized 2,000,000; outstanding at December 31, 2015 – 785,080,314 (excludes 138,812,267 treasury shares), 2014 – 824,046,952 (excludes 99,845,629 treasury shares).

[3] 446,000 shares of undesignated no par value preferred stock are authorized and unissued at December 31, 2015 and 2014; fixed-to-floating rate non-cumulative Series H perpetual preferred stock with a $25,000 liquidation preference: 24,000 authorized shares, issued and outstanding at December 31, 2015 and 2014; fixed-to-floating rate non-cumulative Series I perpetual preferred stock with a $25,000 liquidation preference: 18,000 authorized shares, issued and outstanding at December 31, 2015 and 2014; and fixed-to-floating rate non-cumulative Series J perpetual preferred stock with a $25,000 liquidation preference: 12,000 authorized shares, issued and outstanding at December 31, 2015 and 2014.