Fair Value of Financial instruments (Details 2) - USD ($)	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale Securities			$ 19,130,000
Debt Securities, Available-for-sale	$ 12,260,000		14,541,000
Common Stock, Value, Outstanding	801,000		3,570,000
Equity Securities, FV-NI	856,000		4,589,000
Total equity investments	856,000		4,589,000
Alternative Investment	26,015,000		32,211,000
Investments in private companies, at adjusted cost	3,090,000		4,870,000
Real estate investments, at fair value (cost of $10,225 and 10,225, respectively)	10,662,000		10,662,000	$ 10,662,000
Other Investments	2,079,000		3,721,000
Short-term investments, at cost which approximates fair value	152,000		151,000
Investments	59,904,000		79,839,000
Subordinated Debt	50,023,000		52,105,000
Long-term Debt	246,091,000		244,141,000
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Warrants Not Settleable in Cash, Fair Value Disclosure	55,000		1,019,000
Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale Securities	2,920,000		5,427,000
Debt, State Government [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale Securities	607,000		626,000
US Government Agencies Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale Securities	5,547,000		5,612,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale Securities	3,186,000		2,876,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value	0
Financial Instruments, Owned, Other Sovereign Government Obligations, at Fair Value			0
Warrants Not Settleable in Cash, Fair Value Disclosure	19,000		171,000
Total equity investments	820,000		3,741,000
Other Investments	0		0
Short-term investments, at cost which approximates fair value			0
Investments	820,000		3,741,000
Subordinated Debt	0		0
Long-term Debt	0		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	12,260,000
Warrants Not Settleable in Cash, Fair Value Disclosure	36,000		848,000
Total equity investments	36,000		848,000
Alternative Investment			10,314,000
Investments	14,733,000		29,575,000
Long-term Debt	50,023,000		52,105,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value	0
Alternative Investment	4,124,000		1,397,000	939,000
Real estate investments, at fair value (cost of $10,225 and 10,225, respectively)	10,662,000	$ 10,662,000
Other Investments			0
Short-term investments, at cost which approximates fair value			0
Investments	14,786,000		12,059,000
Subordinated Debt			0
Business Combination, Contingent Consideration, Liability	0		0	$ 325,000
Long-term Debt	0		0
Fair Value, Inputs, Level 3 [Member] | Common Stock [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments in private companies, at adjusted cost	4,124,000.000
Fair Value, Inputs, Level 3 [Member] | Other than Securities Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments	14,786,000		12,059,000
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Alternative Investment	21,685,000		20,500,000
Investments	21,685,000		20,500,000
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total equity investments			4,589,000
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity Securities, FV-NI	801,000		3,570,000
US Government Agencies Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	5,547,000		5,612,000
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial Instruments, Owned, Other Sovereign Government Obligations, at Fair Value			0
Debt Securities, Available-for-sale	5,547,000		5,612,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	3,186,000		2,876,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	0		0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	3,186,000		2,876,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	0		0
Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	2,920,000		5,427,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	0		0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	2,920,000		5,427,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale	0		0
Other Security Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments	52,024,000		65,875,000
Liability [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term Debt	50,023,000
Other Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other Investments	$ 2,079,000		3,721,000
Long-term Debt [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term Debt			$ 52,105,000