Investments (Schedule of Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturities) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Investments [Line Items]
Due in one year or less, Amortized Cost	$ 55,209
Due after one year through five years, Amortized Cost	168,202
Due after five years through ten years, Amortized Cost	106,628
Due after ten years, Amortized Cost	29,899
Debt Maturities, Amortized Cost	411,000
Due in one year or less, Fair Value	55,553
Due after one year through five years, Fair Value	169,167
Due after five years through ten years, Fair Value	105,598
Due after ten years, Fair Value	29,980
Debt Securities, Fair Value	411,262	410,095
Mortgage Backed [Member]
Schedule of Investments [Line Items]
Debt Maturities, Amortized Cost	51,062
Debt Securities, Fair Value	$ 50,964	$ 27,737