Investments (Details) - USD ($)		3 Months Ended								9 Months Ended	12 Months Ended
	May 17, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 14, 2017	Aug. 15, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Income (Loss) from Equity Method Investments											$ (220,000)	$ 0	$ 0
Cash Paid for Investment											2,250,000
Assets, Current		$ 139,695,000				$ 188,490,000					139,695,000	188,490,000
Revenues		$ 3,458,000	$ 36,633,000	$ 16,457,000	$ 8,854,000	21,969,000	$ 64,658,000	$ 41,351,000	$ 24,721,000
Gain on Conversion of Loan and Accrued Interest											2,671,000	0	0
Gain on exercise of Primary Warrant											4,616,000	0	0
Change in fair value of investment											$ 42,239,000	0	0
Percentage of ownership, Veritone	20.00%	23.00%									23.00%
First Loan Warrant															$ 700,000
Time-sharing Transactions, Stated Interest Rate for Notes Receivable															6.00%
Maximum Investment in Veritone															$ 50,000,000
Secured Promissory Note Advance															10,000,000
Veritone Primary Warrant															50,000,000
Secured Convertible Promissory Note															$ 20,000,000
Unamortized loan discount	$ 1,700,000
Investment Income, Interest											$ 1,605,000	798,000	$ (56,000)
Loan receivable and accrued interest	$ 20,700,000	$ 0				18,616,000					0	18,616,000
Investment warrants		0				1,960,000					0	1,960,000
Accretion (Amortization) of Discounts and Premiums, Investments											630,000
Loss on fair value investment net											49,526,000
Assets		308,768,000				296,003,000					308,768,000	296,003,000
Liabilities, Current		9,557,000				28,191,000					9,557,000	28,191,000
Liabilities		13,109,000				28,560,000					13,109,000	28,560,000
Stockholders' Equity Attributable to Parent		$ 294,301,000				$ 265,589,000					$ 294,301,000	$ 265,589,000
Common stock, shares outstanding		50,639,926				50,476,042					50,639,926	50,476,042
Debt Instrument, Convertible, Conversion Price	$ 13.6088
Cash paid for primary warrant exercise	$ 29,300,000
10% Warrant	809,400
Bridge Loan	$ 4,000,000													$ 4,000,000
Bridge loan stated interest rate														8.00%
Veritone Bridge Loan Advance 1														$ 1,000,000
Veritone Bridge Loan Advance 3 and 4														$ 2,000,000
Upfront Shares														60,000
Bridge Installment Shares														90,000
Bridge Warrant Share														157,000
Investments at fair value		$ 104,754,000				$ 0					$ 104,754,000	$ 0
Equity Method Investment, Ownership Percentage		23.00%									23.00%
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable with Imputed Interest, Effective Yield (Interest Rate)											53.00%
Fair Value Assumptions, Expected Volatility Rate											50.00%
Fair Value Inputs, Probability of Default											75.00%
Fair value inputs recovery											100.00%
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable with Imputed Interest, Effective Yield (Interest Rate)											9.00%
Monte Carlo [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Expected Volatility Rate										40.00%
Fair Value Inputs, Discount for Lack of Marketability											7.00%
Fair Value Inputs, Probability of Default											25.00%
Finnerty - Common Stock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Expected Volatility Rate	35.00%										37.00%
Fair Value Inputs, Discount for Lack of Marketability	6.00%										5.00%
Fair Value Assumptions, Expected Term	6 months										2 months
Finnerty - Warrants [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Expected Volatility Rate	35.00%
Fair Value Inputs, Discount for Lack of Marketability	6.00%										10.00%
Fair Value Assumptions, Expected Term	6 months										5 months
Finnerty - Warrants [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Expected Volatility Rate											87.00%
Finnerty - Warrants [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Expected Volatility Rate											72.00%
Black Scholes [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Expected Dividend Payments											$ 0
Black Scholes [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Risk Free Interest Rate											2.37%
Fair Value Assumptions, Expected Volatility Rate											55.00%
Fair Value Assumptions, Expected Term											9 years
Black Scholes [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value Assumptions, Risk Free Interest Rate											1.94%
Fair Value Assumptions, Expected Volatility Rate											45.00%
Fair Value Assumptions, Expected Term											3 years
Veritone [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Assets, Current			78,509,000							$ 78,509,000
Revenues										10,914,000
Investment Income, Interest											$ 1,100,000
Gross Profit										10,090,000
Operating Expenses										44,024,000
Other Operating Income (Expense), Net										(12,872,000)
Net Income (Loss) Available to Common Stockholders, Diluted										$ (51,281,000)
Basic and diluted loss per common share										$ (5,940)
Assets, Noncurrent			1,173,000							$ 1,173,000
Assets			79,682,000							79,682,000
Liabilities, Current			31,836,000							31,836,000
Liabilities, Noncurrent			14,000							14,000
Liabilities			31,850,000							31,850,000
Preferred Stock, Value, Outstanding			0							0
Stockholders' Equity Attributable to Parent			47,832,000							47,832,000
Total liabilities, preferred stock and stockholders' equity			$ 79,682,000							$ 79,682,000
Common Stock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment Owned, Balance, Shares		4,119,521									4,119,521
Investments at fair value		$ 90,795,000									$ 90,795,000
Warrant [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment Owned, Balance, Shares		1,120,432									1,120,432
Investments at fair value		$ 13,959,000									$ 13,959,000
Veritone Loans [Member] | Veritone [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Common stock, shares outstanding	1,523,746
Primary warrant [Member] | Veritone [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Common stock, shares outstanding	2,150,335
Bridge Loan [Member] | Veritone [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Common stock, shares outstanding	295,440
Warrant [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on Conversion of Loan and Accrued Interest											0
Gain on exercise of Primary Warrant											(4,616,000)
Change in fair value of investment											8,317,000
Common Stock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on Conversion of Loan and Accrued Interest											2,671,000
Gain on exercise of Primary Warrant											0
Change in fair value of investment											$ 33,922,000