Investments (Amortized Cost and Aggregate Fair Value of Debt Securities, by Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investments [Abstract]
Available-for-sale Securities, Due in one year or less, Amortized Cost	$ 1,045
Available-for-sale Securities, Due in one year or less, Fair Value	1,062
Available-for-sale Securities, Due after one year through five years, Amortized Cost	15,410
Available-for-sale Securities, Due after one year through five years, Fair Value	16,825
Available-for-sale Securities, Due after five years through ten years, Amortized Cost	23,364
Available-for-sale Securities, Due after five years through ten years, Fair Value	24,813
Available-for-sale Securities, Due after ten years, Amortized Cost	31,859
Available-for-sale Securities, Due after ten years, Fair Value	33,594
Available-for-sale securities, Amortized Cost	71,678	69,980
Available-for-sale Securities, Fair Value	76,294
Held-to-maturity Securities, Due in one year or less, Amortized Cost	0
Held-to-maturity Securities, Due in one year or less, Fair Value	0
Held-to-maturity Securities, Due after one year through five years, Amortized Cost	222
Held-to-maturity Securities, Due after one year through five years, Fair Value	230
Held-to-maturity Securities, Due after five years through ten years, Amortized Cost	305
Held-to-maturity Securities, Due after five years through ten years, Fair Value	327
Held-to-maturity Securities, Due after ten years, Amortized Cost	975
Held-to-maturity Securities, Due after ten years, Fair Value	1,052
Held-to-maturity Securities, Amortized Cost	1,502	3,303
Held-to-maturity Securities, Fair Value	$ 1,609	$ 3,497