Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Cash Flows [Abstract]
Consolidated net loss	$ (134,720,000)	$ (217,570,000)	$ (111,922,000)
Adjustments to reconcile consolidated net loss to net cash used in operating activities:
Depreciation of property and equipment	26,262,000	26,411,000	28,848,000
Amortization of intangible assets	4,769,000	5,286,000	3,999,000
Non-cash operating lease cost	6,676,000	0	0
Stock-based compensation to employees and directors	18,229,000	14,356,000	4,077,000
Deferred income taxes, net	(69,000)	(2,386,000)	65,199,000
Gain on investment in precious metals	0	0	(1,971,000)
Gain on sale of cryptocurrencies	569,000	8,370,000	1,995,000
Impairment of equity securities	334,000	10,463,000	0
Impairment of equity securities	7,090,000	536,000	5,487,000
Losses on equity method securities	(7,734,000)	(3,869,000)	(508,000)
Loss on disposal of business and other asset abandonments	0	3,565,000	0
Impairments on intangible assets	1,406,000	6,000,000	0
Other non-cash adjustments	(2,037,000)	(583,000)	2,832,000
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable, net	13,385,000	(5,558,000)	(1,938,000)
Inventories, net	8,268,000	628,000	5,234,000
Prepaids and other current assets	5,956,000	(3,622,000)	(2,799,000)
Other long-term assets, net	(660,000)	(2,870,000)	(2,307,000)
Accounts payable	(27,158,000)	16,499,000	(20,995,000)
Accrued liabilities	(281,000)	5,661,000	(12,311,000)
Deferred revenue	(8,757,000)	9,150,000	4,688,000
Operating lease liabilities	(8,013,000)	0	0
Other long-term liabilities	543,000	(399,000)	145,000
Net cash used in operating activities	(81,612,000)	(138,934,000)	(35,221,000)
Cash flows from investing activities:
Proceeds from sale of precious metals	0	0	11,917,000
Purchase of intangible assets	0	(9,597,000)	(423,000)
Purchase of equity securities	12,641,000	48,731,000	5,188,000
Proceeds from sale of equity securities and marketable securities	7,339,000	0	0
Disbursement for notes receivable	(4,715,000)	(3,059,000)	(750,000)
Acquisitions of businesses, net of cash acquired	4,886,000	(12,912,000)	0
Deposit on purchase of a business	0	(8,000,000)	0
Expenditures for property and equipment	(21,774,000)	(28,680,000)	(23,586,000)
Other investing activities, net	53,000	56,000	70,000
Net cash used in investing activities	(26,852,000)	(110,923,000)	(17,960,000)
Cash flows from financing activities:
Payments on finance obligations	0	0	(15,316,000)
Payments on interest swap	0	0	(1,535,000)
Payment on long-term debt	(3,141,000)	(40,000,000)	(45,766,000)
Proceeds under short-term contract financing	4,858,000	0	0
Payments under short-term contract financing	(1,353,000)	0	0
Proceeds from long-term debt	0	0	40,000,000
Payments of preferred dividends	(77,000)	(77,000)	(109,000)
Proceeds from issuance and exercise of stock warrants	0	50,588,000	106,462,000
Proceeds from exercise of stock options	0	0	664,000
Proceeds from security token offering, net of offering costs and withdrawals	0	82,354,000	905,000
Proceeds from sale of common stock, net of offering costs	82,954,000	94,554,000	0
Paid in capital for noncontrolling interest	0	(6,700,000)	0
Purchase of treasury stock	0	0	(10,000,000)
Payments of taxes withheld upon vesting of restricted stock	(1,407,000)	(4,622,000)	(1,229,000)
Payment of debt issuance costs	0	0	(670,000)
Other financing activities, net	(1,286,000)	(496,000)	(83,000)
Net cash provided by financing activities	80,548,000	189,001,000	73,323,000
Net increase (decrease) in cash and cash equivalents	(27,916,000)	(60,856,000)	20,142,000
Cash, cash equivalents and restricted cash, beginning of year	142,814,000	203,670,000	183,528,000
Cash, cash equivalents and restricted cash, end of year	114,898,000	142,814,000	203,670,000
Cash paid during the period:
Interest Paid, Excluding Capitalized Interest, Operating Activities	264,000	1,319,000	2,940,000
Income Taxes Paid, Net	(1,259,000)	(726,000)	487,000
Non-cash investing and financing activities:
Property and equipment financed through accounts payable and accrued liabilities	350,000	139,000	989,000
Equipment acquired under capital lease obligations	0	0	1,421,000
Proceeds from sale of common stock included in accounts receivable	2,848,000	0	0
Acquisition of assets through stock issuance	0	4,430,000	0
Change in fair value of cash flow hedge	0	0	(1,738,000)
Common stock repurchased through business combination	643,000	0	0
Note receivable converted to equity investment	2,887,000	200,000	1,368,000
Deposit applied to business combination purchase price	7,347,000	0	0
Equity method security applied to business combination purchase price	3,800,000	0	0
Recognition of right-of-use assets upon adoption of ASC 842	$ 30,968,000	$ 0	$ 0