Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for credit losses on HTM	$ 1,618	$ 2,915
Available-for-sale, allowance for credit loss	2,454	312
Available-for-sale, amortized cost	$ 4,582,052	$ 3,397,043
Preferred stock, Series D, shares authorized (in shares)	40,040,000	40,040,000
Preferred stock, Series D, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, Series D, liquidation value (in dollars per share)	$ 1,000	$ 1,000
Preferred stock, Series D, shares issued (in shares)	767	767
Preferred stock, Series D, shares outstanding (in shares)	767	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)	108,345,732	108,077,662
Common stock, Class A, shares outstanding (in shares)	108,345,732	108,077,662