Consolidated Statements Of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
ASSETS
Securities pledged	$ 10,184,574	$ 9,706,881
Stockholders' Equity Attributable to Parent [Abstract]
Common shares, par value (USD per share)	$ 1	$ 1
Common shares, authorized (in shares)	600,000,000	600,000,000
Common shares, issued and outstanding after deducting shares held in treasury (in shares)	359,815,689	359,425,061
Treasury stock (in shares)	56,575,299	56,947,654