CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets:
Available-for-sale investment securities, pledged amount	$ 427,164	$ 485,414
Available-for-sale investment securities, cost	6,136,544	4,980,102
Equity and other securities, cost	$ 55,665	$ 43,917
Shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	54,188,008	54,092,421
Treasury stock, shares at cost	451,992	214,374
Shares held by deferred compensation arrangements	134,477	146,860