Investments (Major Categories of Net Realized Gains on Investments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Net realized gain	$ 10,540	$ 2,189	$ 3,633
Other-than-temporary impairments		(246)
Gain on investments	10,540	1,943	3,633
U.S. Treasury securities and obligations of U.S. Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Net realized gain			35
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Net realized gain	853	13	300
Collateralized Corporate Bank Loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Net realized gain	373	391	699
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Net realized gain	(156)	(441)	(500)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Net realized gain	$ 9,470	$ 2,226	$ 3,099