Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income/(loss) for the period	$ (18,926)us-gaap_NetIncomeLoss	$ (59,488)us-gaap_NetIncomeLoss	$ (70,656)us-gaap_NetIncomeLoss
Adjustments to reconcile net income/(loss) for the period to net cash used in operations:
Depreciation and amortization	863us-gaap_DepreciationAndAmortization	1,021us-gaap_DepreciationAndAmortization	589us-gaap_DepreciationAndAmortization
Stock-based compensation	1,126us-gaap_ShareBasedCompensation	742us-gaap_ShareBasedCompensation	4,225us-gaap_ShareBasedCompensation
Gain on disposal of marketable securities	(24)us-gaap_MarketableSecuritiesGainLoss	54us-gaap_MarketableSecuritiesGainLoss	(192)us-gaap_MarketableSecuritiesGainLoss
Gain on disposal of mineral property			(2,934)
Unrealized (gain)/loss on other investments	4,267	48,499	50,363
Write down of marketable securities	138	275	39
Write-down of non-current assets	5,563vgz_WriteDownOfNonCurrentAssets	3,500vgz_WriteDownOfNonCurrentAssets	7,367vgz_WriteDownOfNonCurrentAssets
Deferred tax (benefit)/expense		(15,373)us-gaap_DeferredIncomeTaxExpenseBenefit	(20,147)us-gaap_DeferredIncomeTaxExpenseBenefit
Other non-cash items	(162)us-gaap_OtherNoncashExpense	(298)us-gaap_OtherNoncashExpense
Change in working capital account items:
Other current assets	492	1,572	(1,786)
Accounts payable, accrued liabilities and other	(395)	(5,013)	2,977
Net cash used in operating activities	(7,058)	(24,509)	(30,155)
Cash flows from investing activities:
Purchases of marketable securities			(153)
Proceeds from sale of marketable securities and short term investments	60	168	494
Proceeds from Sale of Other Investments	10,560
Additions to plant and equipment	(7)	(2,199)	(2,066)
Change in restricted cash		70	64
Proceeds on disposal of mineral property		7,000
Proceeds from non-current asset disposals	1,028		5,500
Net cash (used in)/provided by investing activities	11,641	5,039	3,839
Cash flows from financing activities:
Net proceeds from equity financings		(13)us-gaap_ProceedsFromOtherEquity	24,472us-gaap_ProceedsFromOtherEquity
Proceeds from exercise of warrants			1,425us-gaap_ProceedsFromWarrantExercises
Proceeds from exercise of compensation options			733
Proceeds from exercise of stock options			94
Net cash provided by financing activities	(6,344)	6,664	26,724
Proceeds from Issuance of Secured Debt	0	9,637
Repayments of Debt	6,344us-gaap_RepaymentsOfDebt	2,960us-gaap_RepaymentsOfDebt
Increase/(decrease) in cash and cash equivalents	(1,761)	(12,806)	408
Cash and cash equivalents, beginning of period	5,475	18,281	17,873
Cash and cash equivalents, end of period	$ 3,714	$ 5,475	$ 18,281

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.