Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities
Debt securities, Cost	$ 4,454	$ 4,458
Debt securities, Carrying Value	4,409	4,453
Total, Cost	15,087	14,797
Total, Gross Unrealized Gains	8,094	7,925
Total, Gross Unrealized Losses	(239)	(132)
Total, Carrying Value	22,942	22,590
Available-for-sale Securities, Debt Maturities [Abstract]
Due in one year or less, Amortized Cost	37	38
Due after one year through five years, Amortized Cost	4,094	2,603
Due after five years, Amortized Cost	323	1,817
Due in one year or less, Carrying Value	38	37
Due after one year through five years, Carrying Value	4,038	2,566
Due after five years, Carrying Value	333	1,850
Corporate Bond Securities
Schedule of Available-for-sale Securities
Debt securities, Cost	4,454	4,458
Debt securities, Gross Unrealized Gains	71	46
Debt securities, Gross Unrealized Losses	(116)	(51)
Debt securities, Carrying Value	4,409	4,453
Equity Securities
Schedule of Available-for-sale Securities
Marketable equity securities, Cost	10,633	10,339
Marketable equity securities, Gross Unrealized Gains	8,023	7,879
Marketable equity securities, Gross Unrealized Losses	(123)	(81)
Marketable equity securities, carrying value	$ 18,533	$ 18,137

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

Name:	us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.