Consolidated Statements Of Condition (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Held-to-maturity securities, fair value	$ 744,286	$ 1,138,396	$ 1,198,478
Allowance for held-to-maturity securities losses	$ 65	$ 0	$ 0
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000	20,000,000
Preferred stock, liquidation value per share (usd per share)	$ 25	$ 25	$ 25
Preferred stock, shares outstanding (in shares)	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	5,000,000	5,000,000	5,000,000
Common stock, $1.00 stated value (usd per share)	$ 1	$ 1	$ 1
Common stock, 100,000,000 shares authorized (in shares)	100,000,000	100,000,000	100,000,000
Common stock, shares issued (in shares)	58,294,456	57,950,803	56,794,328
Treasury stock, (in shares)	720,784	128,912	126,482
Series D Preferred Stock
Preferred stock, liquidation value per share (usd per share)	$ 25	$ 25	$ 25
Preferred stock, shares outstanding (in shares)	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	5,000,000	5,000,000	5,000,000
Series E Preferred Stock
Preferred stock, liquidation value per share (usd per share)	$ 25,000	$ 0	$ 0
Preferred stock, shares outstanding (in shares)	11,500	0	0
Preferred stock, shares issued (in shares)	11,500	0	0