Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
ASSETS
Cash and due from banks	$ 517,803	$ 798,319
Money market investments:
Interest-bearing deposits	3,039,090	6,108,124
Federal funds sold and security resell agreements	1,587,212	619,758
Investment securities:
Available-for-sale, at fair value	8,701,885	7,643,116
Trading account, at fair value	65,838	48,168
Loans held for sale	108,764	149,880
Marketable securities, total	9,399,369	8,236,932
Loans and leases, net of unearned income and fees:
Loans and leases receivable, net of unearned income and fees	41,418,185	40,649,542
Less allowance for loan losses	611,894	606,048
Loans, net of allowance	40,806,291	40,043,494
Other noninterest-bearing investments	855,813	848,144
Premises and equipment, net	925,430	905,462
Goodwill	1,014,129	1,014,129
Core deposit and other intangibles	14,259	16,272
Other Real Estate, Foreclosed Assets, and Repossessed Assets	10,411	7,092
Other assets	901,342	916,937
Total assets	59,179,913	59,664,543
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing demand	21,872,274	22,276,664
Interest-bearing:
Deposits, Savings Deposits	25,723,996	25,672,356
Total deposits	49,887,857	50,374,091
Federal funds and other short-term borrowings	232,188	346,987
Long-term debt	802,448	812,366
Reserve for unfunded lending commitments	69,026	74,838
Other liabilities	562,657	548,742
Total liabilities	51,554,176	52,157,024
Shareholders' equity:
Preferred stock, without par value, authorized 4,400,000 shares	828,490	828,490
Common stock, without par value; authorized 350,000,000 shares; issued and outstanding 204,543,707 and 204,417,093 shares	4,777,630	4,766,731
Retained earnings	2,031,270	1,966,910
Accumulated other comprehensive income (loss)	(11,653)	(54,612)
Total shareholders' equity	7,625,737	7,507,519
Total liabilities and shareholders' equity	59,179,913	59,664,543
Reported Value Measurement [Member]
Investment securities:
Held-to-maturity, at amortized cost (approximate fair value $636,484 and $552,088)	631,646	545,648
Interest-bearing:
Time	2,071,688	2,130,680
Foreign	219,899	294,391
Long-term debt	$ 802,448	$ 812,366