Statements Of Condition (Parenthetical) (USD $) In Thousands, except Per Share data	Jun. 30, 2011	Dec. 31, 2010
Held-to-maturity Securities, Fair value	$ 5,791,136	$ 6,744,289
Capital Stock Class A [Member]
Common Stock, Par Value	$ 100	$ 100
Common Stock, Shares Issued	5,921	5,934
Common Stock, Shares Outstanding	5,921	5,934
Capital Stock Class B [Member]
Common Stock, Par Value	$ 100	$ 100
Common Stock, Shares Issued	7,855	8,610
Common Stock, Shares Outstanding	7,855	8,610