INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2012

Investments [Abstract]

Aggregate Values And Unrealized Gains And Losses Of Investment Securities

The aggregate values of investment securities at December 31, 2012, and 2011, along with gains and losses determined on an individual security basis are as follows:

		Cost		Gross unrealized gains		Gross unrealized losses		Fair value
Investment securities available for sale
2012
	U.S. Treasury	$	823,241	$	403	$	12	$	823,632
	Government agency	3,052,040		3,501		337		3,055,204
	Other	838		—		18		820
	Residential mortgage-backed securities	1,315,211		14,787		341		1,329,657
	Equity securities	543		15,822		—		16,365
	State, county and municipal	546		4		—		550
	Total investment securities available for sale	$	5,192,419	$	34,517	$	708	$	5,226,228
2011
	U.S. Treasury	$	887,041	$	808	$	30	$	887,819
	Government agency	2,591,974		1,747		1,512		2,592,209
	Corporate bonds	250,476		2,344		—		252,820
	Residential mortgage-backed securities	298,402		9,165		346		307,221
	Equity securities	939		14,374		—		15,313
	State, county and municipal	1,026		16		1		1,041
	Total investment securities available for sale	$	4,029,858	$	28,454	$	1,889	$	4,056,423
Investment securities held to maturity
2012
	Residential mortgage-backed securities	$	1,342	$	133	27		$	1,448
2011
	Residential mortgage-backed securities	$	1,822	$	184	26		$	1,980

Investment Securities Maturity Information

The following table provides maturity information for investment securities as of December 31, 2012, and 2011. Callable agency securities are assumed to mature on their earliest call date. Maturity information for residential mortgage-backed securities is adjusted to reflect estimated prepayments.

	2012				2011
	Cost		Fair value		Cost		Fair value
Investment securities available for sale
Maturing in:
One year or less	$	2,288,556	$	2,289,859	$	3,238,657	$	3,241,415
One through five years	2,323,222		2,329,207		548,459		549,351
Five through 10 years	194,398		196,371		90,605		91,087
Over 10 years	385,700		394,426		151,198		159,257
Equity securities	543		16,365		939		15,313
Total investment securities available for sale	$	5,192,419	$	5,226,228	$	4,029,858	$	4,056,423
Investment securities held to maturity
Maturing in:
One through five years	$	1,242	$	1,309	$	12	$	11
Five through 10 years	18		11		1,699		1,820
Over 10 years	82		128		111		149
Total investment securities held to maturity	$	1,342	$	1,448	$	1,822	$	1,980

Securities Gains (Losses)

For each period presented, securities gains (losses) include the following:

	2012			2011			2010
Gross gains on sales of investment securities available for sale	$	2,324		$	531		$	4,103
Gross losses on sales of investment securities available for sale	(2		)	(793		)	(1,730		)
Other than temporary impairment losses on equity investments	(45		)	(26		)	(421		)
Total securities gains (losses)	$	2,277		$	(288	)	$	1,952

Investment Securities With Unrealized Losses

The following table provides information regarding securities with unrealized losses as of December 31, 2012, and 2011:

	Less than 12 months				12 months or more				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
December 31, 2012
Investment securities available for sale:
U.S. Treasury	$	120,045	$	12	$	—	$	—	$	120,045	$	12
Government agency	407,498		337		—		—		407,498		337
Residential mortgage-backed securities	135,880		214		9,433		127		145,313		341
Other	820		18		—		—		820		18
Total	$	664,243	$	581	$	9,433	$	127	$	673,676	$	708
Investment securities held to maturity:
Residential mortgage-backed securities	$	—	$	—	$	17	$	27	$	17	$	27
Total	$	—	$	—	$	17	$	27	$	17	$	27
December 31, 2011
Investment securities available for sale:
U.S. Treasury	$	151,269	$	30	$	—	$	—	$	151,269	$	30
Government agency	1,336,763		1,512		—		—		1,336,763		1,512
Residential mortgage-backed securities	59,458		304		1,380		42		60,838		346
State, county and municipal	—		—		10		1		10		1
Total	$	1,547,490	$	1,846	$	1,390	$	43	$	1,548,880	$	1,889
Investment securities held to maturity:
Residential mortgage-backed securities	$	—	$	—	$	21	$	26	$	21	$	26
Total	$	—	$	—	$	21	$	26	$	21	$	26