Investment Securities, Securities Sales And Continuous Unrealized Loss Position Of Securities Held (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 Security	Mar. 31, 2012	Dec. 31, 2012 Security
Proceeds from sales of securities available for sale and the associated realized securities gains and losses [Abstract]
Proceeds	$ 10,475	$ 0
Gross realized gains	359	0
Gross realized losses	0	0
Net Gain on Sale of Securities Available for Sale	359	0
Length of time individual securities for held-to-maturity and available-for-sale held in a continuous unrealized loss position [Abstract]
Number of Securities	22		12
Less than 12 months estimated fair value	85,213		50,934
Less than 12 months unrealized losses	565		223
12 months or longer estimated fair value	0		0
12 months or longer unrealized losses	0		0
Total estimated fair value	85,213		50,934
Total unrealized losses	565		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]
Number of Securities	8		6
Less than 12 months estimated fair value	38,820		28,958
Less than 12 months unrealized losses	204		77
12 months or longer estimated fair value	0		0
12 months or longer unrealized losses	0		0
Total estimated fair value	38,820		28,958
Total unrealized losses	204		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]
Number of Securities	3		2
Less than 12 months estimated fair value	10,177		7,878
Less than 12 months unrealized losses	69		80
12 months or longer estimated fair value	0		0
12 months or longer unrealized losses	0		0
Total estimated fair value	10,177		7,878
Total unrealized losses	69		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]
Number of Securities	9		4
Less than 12 months estimated fair value	30,696		14,098
Less than 12 months unrealized losses	277		66
12 months or longer estimated fair value	0		0
12 months or longer unrealized losses	0		0
Total estimated fair value	30,696		14,098
Total unrealized losses	277		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]
Number of Securities	2
Less than 12 months estimated fair value	5,520
Less than 12 months unrealized losses	15
12 months or longer estimated fair value	0
12 months or longer unrealized losses	0
Total estimated fair value	5,520
Total unrealized losses	$ 15