Investments (Schedule of Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Investments [Line Items]
Due in one year or less, Amortized Cost	$ 59,432
Due after one year through five years, Amortized Cost	174,590
Due after five years through ten years, Amortized Cost	107,098
Due after ten years, Amortized Cost	31,010
Debt Maturities, Amortized Cost	424,760
Due in one year or less, Fair Value	59,573
Due after one year through five years, Fair Value	176,780
Due after five years through ten years, Fair Value	107,371
Due after ten years, Fair Value	31,003
Debt Securities, Fair Value	427,147	410,095
Mortgage Backed [Member]
Schedule of Investments [Line Items]
Debt Maturities, Amortized Cost	52,630
Debt Securities, Fair Value	$ 52,420	$ 27,737