5. Securities (Summary of Volume of State and Political Subdivision Securities Held in Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Available for sale securities, Amortized Cost	$ 279,511	$ 275,522	$ 289,614
Available for sale securities, Unrealized Gains	4,820	8,644	3,851
Available for sale securities, Unrealized Losses	2,466	1,112	4,685
Available for sale securities, Estimated Fair Value	281,865	283,054	288,780
California [Member]
Available for sale securities, Amortized Cost	16,625
Available for sale securities, Unrealized Gains	207
Available for sale securities, Unrealized Losses	119
Available for sale securities, Estimated Fair Value	16,713
West Virginia [Member]
Available for sale securities, Amortized Cost	13,642
Available for sale securities, Unrealized Gains	203
Available for sale securities, Unrealized Losses	109
Available for sale securities, Estimated Fair Value	13,736
Illinois [Member]
Available for sale securities, Amortized Cost	9,392
Available for sale securities, Unrealized Gains	75
Available for sale securities, Unrealized Losses	238
Available for sale securities, Estimated Fair Value	9,229
Texas [Member]
Available for sale securities, Amortized Cost	6,262
Available for sale securities, Unrealized Gains	313
Available for sale securities, Unrealized Losses	78
Available for sale securities, Estimated Fair Value	6,497
Pennsylvania [Member]
Available for sale securities, Amortized Cost	5,906
Available for sale securities, Unrealized Gains	25
Available for sale securities, Unrealized Losses	71
Available for sale securities, Estimated Fair Value	$ 5,860