Available for Sale Securities (Schedule of Available-for-sale Securities in Continuous Unrealized Loss Position) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value:
Less Than or Equal to One Year	$ 5,158	$ 7,796
More Than One Year	1,304	923
Gross Unrealized Losses:
Less Than or Equal to One Year	(49)	(144)
More Than One Year	(23)	(14)
U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value:
Less Than or Equal to One Year	3,408	5,543
More Than One Year	1,155	854
Gross Unrealized Losses:
Less Than or Equal to One Year	(34)	(102)
More Than One Year	(23)	(14)
Corporate securities
Fair Value:
Less Than or Equal to One Year	1,750	2,253
More Than One Year	147	67
Gross Unrealized Losses:
Less Than or Equal to One Year	(15)	(42)
More Than One Year	0	0
Asset-backed securities
Fair Value:
Less Than or Equal to One Year	0	0
More Than One Year	2	2
Gross Unrealized Losses:
Less Than or Equal to One Year	0	0
More Than One Year	$ 0	$ 0