Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Feb. 16, 2017
Summary of Significant Accounting Policies [Line Items]
Short-term investments - debt securities	$ 30,837,000	$ 0		$ 30,837,000
Investment in common stock	32,538,000	90,795,000		32,538,000
Investment warrants	4,110,000	13,959,000		4,110,000
Other Cost of Operating Revenue	0		$ 0	4,000,000	$ 0
Short-term investments	66,386,000			66,386,000
Available-for-sale Securities, Amortized Cost Basis	30,843,000			30,843,000
Available-for-sale Debt Securities Gross Unrealized Gain				0
Available-for-sale Debt Securities, Gross Unrealized Loss				6,000
Available-for-sale Securities, Gross Unrealized Gain				0
Available-for-sale Securities, Gross Unrealized Loss				(6,000)
Available-for-sale Securities	33,848,000			33,848,000
Investments at fair value	36,648,000	104,754,000		36,648,000
Unrealized Gain (Loss) on Investments - Common Stock				(42,278,000)
Unrealized Gain (Loss) on Investment - Warrants				(9,849,000)
Fair Value of Profits Interest	1,422,000	3,041,000		1,422,000		$ 722,000
Non-cash stock compensation - profits interests	(576,000)		8,181,000	(1,619,000)	8,235,000
Change in fair value of investment, net	(22,377,000)		158,979,000	(52,127,000)	146,281,000
Loss on Sale of Investments	$ (5,539,000)		$ 0	(5,539,000)	$ 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchases, Sales, and Settlements				(10,440,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3				(32,538,000)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Write-down of deferred tax assets		25,261,000
Available-for-sale Equity Securities, Amortized Cost Basis	$ 2,930,000			2,930,000
Available-for-sale Securities, Gross Realized Gains				81,000
Short-term investments - equity securities	3,011,000	$ 0		3,011,000
Available-for-sale Securities, Amortized Cost Basis	$ 33,773,000			$ 33,773,000
Effective tax rate	(1.00%)		0.00%	1.00%	(2.00%)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	$ (32,558,000)		$ 158,585,000	$ (92,699,000)	$ 134,919,000
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Useful life of patents and patent rights				1 year
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Useful life of patents and patent rights				5 years
Fair Value Assumptions, Expected Volatility Rate				50.00%
Geometric Brownian Motion [Member]
Summary of Significant Accounting Policies [Line Items]
Fair Value Assumptions, Expected Term				4 years
Geometric Brownian Motion [Member] | Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Fair Value Assumptions, Expected Volatility Rate				50.00%
Fair Value Assumptions, Risk Free Interest Rate				2.00%
Geometric Brownian Motion [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Fair Value Assumptions, Expected Volatility Rate				70.00%
Fair Value Assumptions, Risk Free Interest Rate				3.00%