Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS:
Held to maturity securities, fair value	$ 26,994	$ 28,701
SHAREHOLDERS' EQUITY:
Capital stock, par value (in dollars per share)	$ 1	$ 1
Capital stock, shares authorized (in shares)	150,000,000	150,000,000
Capital stock, shares issued (in shares)	100,002,482	99,998,482
Treasury stock, at cost (in shares)	3,643,882	3,709,171