Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Available-for-sale, allowance for credit loss	$ 68	$ 0
Loans held for sale, fair value	$ 1,368,044	$ 1,656,711
Preferred stock, stated value (in dollars per share)	$ 1,000	$ 1,000
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares Issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	200,000,000	100,000,000
Common stock, shares issued (in shares)	71,702,587	71,499,829
Treasury stock, shares (in shares)	2,212,041	1,995,996