Investments (Amortized Cost and Aggregate Fair Value of Debt Securities, by Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Investments [Abstract]
Available-for-sale Securities, Due in one year or less, Amortized Cost	$ 1,115
Available-for-sale Securities, Due in one year or less, Fair Value	1,134
Available-for-sale Securities, Due after one year through five years, Amortized Cost	14,420
Available-for-sale Securities, Due after one year through five years, Fair Value	15,489
Available-for-sale Securities, Due after five years through ten years, Amortized Cost	21,148
Available-for-sale Securities, Due after five years through ten years, Fair Value	22,329
Available-for-sale Securities, Due after ten years, Amortized Cost	32,253
Available-for-sale Securities, Due after ten years, Fair Value	33,494
Available-for-sale securities, Amortized Cost	68,936	69,980
Available-for-sale Securities, Fair Value	72,446
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	516
Held-to-maturity Securities, Due after one year through five years, Fair Value	544
Held-to-maturity Securities, Due after five years through ten years, Amortized Cost	473
Held-to-maturity Securities, Due after five years through ten years, Fair Value	507
Held-to-maturity Securities, Due after ten years, Amortized Cost	1,347
Held-to-maturity Securities, Due after ten years, Fair Value	1,450
Held-to-maturity Securities, Amortized Cost	2,336	3,303
Held-to-maturity Securities, Fair Value	$ 2,501	$ 3,497