Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014 investment	Dec. 31, 2013 investment
Schedule of Available-for-sale Securities [Line Items]
Total number in loss position (investments)	2	1
Less than twelve months - fair values	$ 10,492	$ 12,460
Less than twelve months - unrealized losses	(23)	(229)
Twelve months or greater - fair values	0	0
Twelve months or greater - unrealized losses	0	0
Total Fair Value	10,492	12,460
Total Unrealized Losses	(23)	(229)
Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Total number in loss position (investments)	2	1
Less than twelve months - fair values	10,492	12,460
Less than twelve months - unrealized losses	(23)	(229)
Twelve months or greater - fair values	0	0
Twelve months or greater - unrealized losses	0	0
Total Fair Value	10,492	12,460
Total Unrealized Losses	$ (23)	$ (229)
Unrestricted Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments with other than temporary impairments (investments)	0