Net Securities Gains (Losses) (Tables)

12 Months Ended

Dec. 31, 2011

Net Securities Gains (Losses) [Abstract]

Summary Of Net Securities Gains (Losses)

	2011			2010			2009
Net realized gains on securities	$	644,777		$	182,060		$	10,440
Write-down of investments (a)		(3,586	)		(2,474	)		(31,420	)
Net unrealized gains (losses) on trading securities		285			(92	)		(126	)
	$	641,476		$	179,494		$	(21,106	)

(a)   Consists of provisions to write down investments resulting from declines in fair values believed to be other than temporary.