Investments (Amortized Cost and Aggregate Fair Value of Debt Securities, by Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Investments [Abstract]
Available-for-sale Securities, Due in one year or less, Amortized Cost	$ 1,155
Available-for-sale Securities, Due in one year or less, Fair Value	1,185
Available-for-sale Securities, Due after one year through five years, Amortized Cost	15,140
Available-for-sale Securities, Due after one year through five years, Fair Value	16,257
Available-for-sale Securities, Due after five years through ten years, Amortized Cost	26,309
Available-for-sale Securities, Due after five years through ten years, Fair Value	26,726
Available-for-sale Securities, Due after ten years, Amortized Cost	33,661
Available-for-sale Securities, Due after ten years, Fair Value	33,434
Available-for-sale securities, Amortized Cost	76,265	71,678
Available-for-sale Securities, Fair Value	77,602
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	271
Held-to-maturity Securities, Due after one year through five years, Fair Value	285
Held-to-maturity Securities, Due after five years through ten years, Amortized Cost	195
Held-to-maturity Securities, Due after five years through ten years, Fair Value	207
Held-to-maturity Securities, Due after ten years, Amortized Cost	412
Held-to-maturity Securities, Due after ten years, Fair Value	439
Held-to-maturity Securities, Amortized Cost	878	1,502
Held-to-maturity Securities, Fair Value	$ 931	$ 1,609