Investment Securities, Securities Sales And Continuous Unrealized Loss Position Of Securities Held (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Proceeds from sales of securities available for sale and the associated realized securities gains and losses [Abstract]
Proceeds	$ 0	$ 3,584	$ 13,427	$ 3,584
Gross realized gains	3	0	395	0
Gross realized losses	0	162	0	162
Net gain (loss) on sale of securities available for sale	3	(162)	395	(162)
Length of time individual securities for held-to-maturity and available-for-sale held in a continuous unrealized loss position [Abstract]
Less than 12 months estimated fair value	214,930		214,930		50,934
Less than 12 months unrealized losses	11,849		11,849		223
12 months or longer estimated fair value	4,764		4,764		0
12 months or longer unrealized losses	79		79		0
Total estimated fair value	219,694		219,694		50,934
Total unrealized losses	11,928		11,928		223
U.S. Government Agency Securities [Member]
Length of time individual securities for held-to-maturity and available-for-sale held in a continuous unrealized loss position [Abstract]
Less than 12 months estimated fair value	102,510		102,510		28,958
Less than 12 months unrealized losses	6,828		6,828		77
12 months or longer estimated fair value	0		0		0
12 months or longer unrealized losses	0		0		0
Total estimated fair value	102,510		102,510		28,958
Total unrealized losses	6,828		6,828		77
Collateralized Mortgage Obligations [Member]
Length of time individual securities for held-to-maturity and available-for-sale held in a continuous unrealized loss position [Abstract]
Less than 12 months estimated fair value	8,900		8,900		7,878
Less than 12 months unrealized losses	660		660		80
12 months or longer estimated fair value	0		0		0
12 months or longer unrealized losses	0		0		0
Total estimated fair value	8,900		8,900		7,878
Total unrealized losses	660		660		80
Mortgage-Backed Securities [Member]
Length of time individual securities for held-to-maturity and available-for-sale held in a continuous unrealized loss position [Abstract]
Less than 12 months estimated fair value	94,848		94,848		14,098
Less than 12 months unrealized losses	4,143		4,143		66
12 months or longer estimated fair value	4,764		4,764		0
12 months or longer unrealized losses	79		79		0
Total estimated fair value	99,612		99,612		14,098
Total unrealized losses	4,222		4,222		66
Corporate Bond Securities [Member]
Length of time individual securities for held-to-maturity and available-for-sale held in a continuous unrealized loss position [Abstract]
Less than 12 months estimated fair value	8,672		8,672
Less than 12 months unrealized losses	218		218
12 months or longer estimated fair value	0		0
12 months or longer unrealized losses	0		0
Total estimated fair value	8,672		8,672
Total unrealized losses	$ 218		$ 218