Investment Securities (Continuous Unrealized Loss Position) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, estimated fair value	$ 134,237	$ 137,577
Less than 12 months, gross unrealized losses	1,375	2,193
12 months or more, estimated fair value	7,027	16,552
12 months or more, gross unrealized losses	44	180
Total, estimated fair value	141,264	154,129
Total, gross unrealized losses	1,419	2,373
Obligations of U.S. government sponsored agencies [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, estimated fair value		21,248
Less than 12 months, gross unrealized losses		151
12 months or more, estimated fair value		0
12 months or more, gross unrealized losses		0
Total, estimated fair value		21,248
Total, gross unrealized losses		151
Obligations of states and political subdivisions [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, estimated fair value		1,907
Less than 12 months, gross unrealized losses		1
12 months or more, estimated fair value		0
12 months or more, gross unrealized losses		0
Total, estimated fair value		1,907
Total, gross unrealized losses		1
Residential mortgage-backed securities - GSE [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, estimated fair value	123,489	89,730
Less than 12 months, gross unrealized losses	904	1,042
12 months or more, estimated fair value	7,027	16,552
12 months or more, gross unrealized losses	44	180
Total, estimated fair value	130,516	106,282
Total, gross unrealized losses	948	1,222
Residential mortgage-backed securities - Private [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, estimated fair value	7,499	21,519
Less than 12 months, gross unrealized losses	454	967
12 months or more, estimated fair value	0	0
12 months or more, gross unrealized losses	0	0
Total, estimated fair value	7,499	21,519
Total, gross unrealized losses	454	967
Corporate notes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, estimated fair value	3,249	3,173
Less than 12 months, gross unrealized losses	17	32
12 months or more, estimated fair value	0	0
12 months or more, gross unrealized losses	0	0
Total, estimated fair value	3,249	3,173
Total, gross unrealized losses	$ 17	$ 32