Consolidated Statements Of Condition (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Held-to-maturity securities, fair value	$ 1,036,096	$ 812,516
Preferred stock, authorized (in shares)	20,000,000	20,000,000
Common stock, stated value (in usd per share)	$ 1.00	$ 1.00
Common stock, authorized (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	56,518,119	56,068,220
Treasury stock (in shares)	110,561	103,013
Series D preferred stock
Preferred stock, liquidation value (in usd per share)	$ 25	$ 25
Preferred stock, issued (in shares)	5,000,000	5,000,000
Preferred stock, outstanding (in shares)	5,000,000	5,000,000