CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Interest receivable - Consolidated Trusts amount	$ 199,195,000	$ 180,080,000
Accrued interest payable - Consolidated Trusts amount	106,959,000	96,743,000
Variable Interest Entity, Primary Beneficiary
Interest receivable - Consolidated Trusts amount	20,568,000	19,783,000
Accrued interest payable - Consolidated Trusts amount	$ 18,018,000	$ 17,125,000
5.875% Non-Cumulative Preferred Stock, Series A
Preferred stock, par value (in dollars per share)	$ 25	$ 25
Preferred stock, shares authorized (in shares)	2,400,000	2,400,000
Preferred stock, shares issued (in shares)	2,400,000	2,400,000
Preferred stock, shares outstanding (in shares)	2,400,000	2,400,000
Series B Preferred Stock
Preferred stock, par value (in dollars per share)	$ 25	$ 25
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Preferred stock, shares issued (in shares)	3,000,000	3,000,000
Preferred stock, shares outstanding (in shares)	3,000,000	3,000,000
Preferred stock, redemption amount	$ 75,000,000	$ 75,000,000
6.000% Fixed-to-Floating Rate Non-Cumulative Preferred Stock, Series C
Preferred stock, par value (in dollars per share)	$ 25	$ 25
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Preferred stock, shares issued (in shares)	3,000,000	3,000,000
Preferred stock, shares outstanding (in shares)	3,000,000	3,000,000
5.700% Non-Cumulative Preferred Stock, Series D
Preferred stock, par value (in dollars per share)	$ 25	$ 25
Preferred stock, shares authorized (in shares)	4,000,000	4,000,000
Preferred stock, shares issued (in shares)	4,000,000	4,000,000
Preferred stock, shares outstanding (in shares)	4,000,000	4,000,000
Class A voting common stock
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares outstanding (in shares)	1,030,780	1,030,780
Common Class B, Voting
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares outstanding (in shares)	500,301	500,301
Class C non-voting common stock
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares outstanding (in shares)	9,180,744	9,137,550

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