Investments (Amortized Cost and Aggregate Fair Value of Debt Securities, by Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Investments [Abstract]
Available-for-sale Securities, Due in one year or less, Amortized Cost	$ 1,695
Available-for-sale Securities, Due in one year or less, Fair Value	1,737
Available-for-sale Securities, Due after one year through five years, Amortized Cost	14,867
Available-for-sale Securities, Due after one year through five years, Fair Value	15,990
Available-for-sale Securities, Due after five years through ten years, Amortized Cost	24,381
Available-for-sale Securities, Due after five years through ten years, Fair Value	24,823
Available-for-sale Securities, Due after ten years, Amortized Cost	33,632
Available-for-sale Securities, Due after ten years, Fair Value	33,810
Available-for-sale securities, Amortized Cost	74,575	71,678
Available-for-sale Securities, Fair Value	76,360
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	445
Held-to-maturity Securities, Due after one year through five years, Fair Value	465
Held-to-maturity Securities, Due after five years through ten years, Amortized Cost	27
Held-to-maturity Securities, Due after five years through ten years, Fair Value	28
Held-to-maturity Securities, Due after ten years, Amortized Cost	665
Held-to-maturity Securities, Due after ten years, Fair Value	706
Held-to-maturity Securities, Amortized Cost	1,137	1,502
Held-to-maturity Securities, Fair Value	$ 1,199	$ 1,609