Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for credit losses on HTM	$ 1,279	$ 2,915
Available-for-sale, allowance for credit loss	0	312
Available-for-sale, amortized cost	$ 7,130,861	$ 3,397,043
Preferred stock, Series D, shares authorized (in shares)		40,040,000
Preferred stock, Series D, par value (in dollars per share)		$ 0.01
Preferred stock, Series D, liquidation value (in dollars per share)		$ 1,000
Preferred stock, Series D, shares issued (in shares)		767
Preferred stock, Series D, shares outstanding (in shares)		767
Common stock, Class A, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, Class A, shares authorized (in shares)	175,000,000	175,000,000
Common stock, Class A, shares issued (in shares)	112,715,444	108,077,662
Common stock, Class A, shares outstanding (in shares)	112,715,444	108,077,662