CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Interest receivable - Consolidated Trusts amount	$ 85,522	$ 122,782
Accrued interest payable - Consolidated Trusts amount	$ 46,845	$ 49,700
Series A Preferred Stock [Member]
Preferred stock, par value	$ 25	$ 25
Preferred stock, shares authorized	2,400,000	2,400,000
Preferred Stock, Shares Issued	2,400,000	2,400,000
Preferred Stock, Shares Outstanding	2,400,000	2,400,000
Series B Preferred Stock [Member]
Preferred stock, par value	$ 25	$ 25
Preferred stock, shares authorized	3,000,000	3,000,000
Preferred Stock, Shares Issued	3,000,000	3,000,000
Preferred Stock, Shares Outstanding	3,000,000	3,000,000
Series C Preferred Stock [Member]
Preferred stock, par value	$ 25	$ 25
Preferred stock, shares authorized	3,000,000	3,000,000
Preferred Stock, Shares Issued	3,000,000	3,000,000
Preferred Stock, Shares Outstanding	3,000,000	3,000,000
Common Class A, Voting [Member]
Common stock, par value	$ 1	$ 1
Common stock, shares outstanding	1,030,780	1,030,780
Common Class B, Voting [Member]
Common stock, par value	$ 1	$ 1
Common stock, shares outstanding	500,301	500,301
Common Class C, Non-Voting [Member]
Common stock, par value	$ 1	$ 1
Common stock, shares outstanding	9,065,194	9,007,481
Variable Interest Entity, Primary Beneficiary [Member]
Interest receivable - Consolidated Trusts amount	$ 8,163	$ 12,584
Accrued interest payable - Consolidated Trusts amount	$ 6,771	$ 10,881