Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.30(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Additional Paid-in Capital (Details) In Thousands, except Share data, unless otherwise specified	6 Months Ended						6 Months Ended	12 Months Ended	1 Months Ended		1 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended	6 Months Ended
	Jun. 30, 2012 USD ($)	Apr. 18, 2012 USD ($)	Mar. 13, 2012 CAD	Dec. 31, 2011	Apr. 20, 2011 USD ($)	Apr. 20, 2011 CAD	Jun. 30, 2012 Warrant [Member] USD ($)	Dec. 31, 2011 Warrant [Member] USD ($)	Oct. 31, 2015 Warrant [Member] In October 2015 [Member]	Jun. 30, 2012 Warrant [Member] In October 2015 [Member]	Oct. 31, 2012 Warrant [Member] In October 2012 [Member]	Jun. 30, 2012 Warrant [Member] In October 2012 [Member]	Jun. 30, 2012 Compensation Options [Member] USD ($)	Jun. 30, 2012 Stock Options [Member] USD ($)	Dec. 31, 2011 Stock Options [Member] USD ($)	Jun. 30, 2012 Restricted Stock Units (RSUs) [Member] USD ($)	Jun. 30, 2011 Restricted Stock Units (RSUs) [Member] USD ($)	Jun. 30, 2012 Restricted Stock Units (RSUs) [Member] USD ($)	Jun. 30, 2011 Restricted Stock Units (RSUs) [Member] USD ($)	Jun. 30, 2012 Stock Option Plan [Member] USD ($)	Jun. 30, 2011 Stock Option Plan [Member] USD ($)	Jun. 30, 2012 Stock Option Plan [Member] USD ($)	Jun. 30, 2011 Stock Option Plan [Member] USD ($)	Dec. 31, 2011 Stock Option Plan [Member] USD ($)	Jun. 30, 2012 Long Term Equity Incentive Plan [Member]	Jun. 30, 2012 Long Term Equity Incentive Plan [Member] Director [Member] USD ($)	Jun. 30, 2012 Long Term Equity Incentive Plan [Member] Restricted Stock Units (RSUs) [Member] USD ($)	Jun. 30, 2012 Long Term Equity Incentive Plan [Member] Restricted Stock Units (RSUs) [Member] Director [Member]	Jun. 30, 2012 Warrants [Member] USD ($)	Jun. 30, 2012 Stock Based Compensation [Member] USD ($)	Jun. 30, 2012 Compensation Options [Member] USD ($)	Jun. 30, 2012 Other Paid-In Capital [Member] USD ($)	Jun. 30, 2012 Additional Paid-in Capital [Member] USD ($)
Additional Paid in Capital [Roll Forward]
Balance, beginning of year																													$ 10,288	$ 5,065	$ 588	$ 8,729	$ 24,670
Warrant exercise																													(464)	0	0	464	0
Stock options expensed	442																												0	442	0	0	442
Restricted stock units expensed	1,550																												0	1,550	0	0	1,550
Compensation options exercised	733																												0	0	(294)	294	0
Balance, end of period																													9,824	7,057	294	9,487	26,662
Warrants [Roll Forward]
Warrants valuation							9,824	10,288
Warrants valuation, exercised							(464)
Warrants exercised, outstanding and exercisable (in shares)								15,850,238
Warrants exercised (in shares)							(478,261)
Warrants outstanding (in shares)							15,371,977
Weighted average exercise price per share, exercised (in dollars per share)							$ 3.49	$ 3.45
Weighted average remaining life (yrs.)							3 years 3 months 19 days	3 years 8 months 12 days					9 months 18 days
Intrinsic Value							93	485
Number of warrants expected to expire in future (in shares)							15,371,977			15,219,802		152,175
Expiry Date									Oct. 31, 2015		Oct. 31, 2012		Apr. 30, 2013
Compensation options, beginning of period (in shares)													450,000
Exercise (in shares)	(225,000)												(225,000)
Compensation options, end of period (in shares)													225,000
Valuation, beginning of period													588
Valuation, exercise													(294)
Valuation, end of period													294
Options, number of shares [Roll forward]
Outstanding, beginning of period (in shares)																						3,195,000
Granted (in shares)																							671
Outstanding, end of period (in shares)																				3,195,000		3,195,000		3,195,000
Exercisable, end of period (in shares)																				3,017,500		3,017,500
Weighted average remaining life (yrs.)																						2 years 2 months 22 days
Weighted Average Remaining Contractual Term																						2 years 1 month 13 days		2 years 8 months 22 days
Options, weighted average exercise price per share [Roll Forward]
Outstanding, beginning of period (in dollars per share)																						$ 3.27
Outstanding, end of period (in dollars per share)																				$ 3.27		$ 3.27		$ 3.27
Exercisable, end of period (in dollars per share)																				$ 3.25		$ 3.25
Share price (in dollars per share)		$ 2.30	3.30		$ 3.43	3.30
Stock compensation plans [Roll Forward]
Balance, beginning of period	141,223													5,065	4,695																		24,670
Stock options														442	238
Restricted stock units														1,550	132
Balance, end of period	103,094													7,057	5,065																		26,662
Common shares reserved for issuance (in hundredths)																				10.00%		10.00%
Number of shares reserved for issuance (in shares)																				7,220,714		7,220,714
Issued and outstanding common shares (in shares)	72,207,144			71,503,883																72,207,144		72,207,144
Term of award	10 years
Options, additional disclosures [Abstract]
Outstanding, aggregate intrinsic value, beginning of period																						1,039
Outstanding, aggregate intrinsic value, end of period																				792		792		1,039
Exercisable, aggregate intrinsic value																				792		792
Percentage of total number of options outstanding (in hundredths)																						4.42%
Compensation expense																775	75	1,550	165	205	735	442	783
Aggregate intrinsic value of options exercised																							224
Unvested at beginning of year (in shares)																						597,500
Vested (in shares)																						(420,000)
Unvested at end of period																				177,500		177,500		597,500
Unvested at beginning of period, weighted average grant date fair value (in dollars per share)																						$ 1.60
Vested, weighted average grant-date fair value (in dollars per share)																						$ 1.51
Unvested at end of period, weighted average grant date fair value (in dollars per share)																				$ 1.82		$ 1.82		$ 1.60
Unrecognized compensation expense related to unvested options																				73		73
Unrecognized compensation expense related to unvested RSU awards outstanding																											2,955
Weighted average period for recognition																						3 months 14 days					1 year 3 months 25 days
Percentage of total number of common shares issuable or issued (in hundredths)																									1.00%
Annual award value per director																										$ 100
Equity instruments other than options, nonvested, number of units [Roll Forward]
Unvested, beginning of period (in shares)																											660,000
Granted (in shares)																											350,000
Unvested, end of period (in shares)																											1,310,000
Equity instruments other than options, unvested, weighted average grant date fair value [Roll Forward]
Unvested, beginning of period (in dollars per share)																											$ 3.84
Granted (in dollars per share)																											$ 3.07
Unvested, end of period (in dollars per share)																											$ 3.63
Award vesting terms																											660,000 of the RSU awards granted vest as follows: a) 50% vest after three years; b) 25% vest at the time that a definitive investment decision or significant transaction, as confirmed by the Board, is made for Mt. Todd; c) 12.5% vest upon the completion of a positive preliminary feasibility study for the Guadalupe de los Reyes gold/silver project as set out in a technical report that has been filed on SEDAR at www.sedar.com by the Corporation; and d) 12.5% vest upon the addition of 1.5 million ounces of estimated measured and indicated mineral resources to Vista's resource holdings, which estimated resources are set out in a technical report that has been filed on SEDAR at www.sedar.com by the Corporation. The vesting period for all RSUs shall be at least one year. The remaining 300,000 RSU awards granted vest when the average adjusted value of the common shares (or common shares plus dividends or distribution value) measured over any consecutive 30-day period is two times the closing trading price of the common shares as listed on the NYSE Amex Exchange on November 2, 2011 of $3.78, provided that this period is at least one year after the grant date of the RSUs. The adjusted value is the closing trading price of the common shares as listed on the NYSE Amex Exchange (on any given day) divided by one (1) plus the percentage change (increase/decrease) from date the RSUs were granted to the current date of the average of the AMEX Gold Basket of Unhedged Gold Stocks Index ("HUI") and the Philadelphia Gold and Silver Sector Index ("XAU"). In the event the share price vesting provision is met prior to the end of one year, the RSUs will vest at the end of one year regardless of the share price at that time. Upon vesting, a holder of an RSU award will receive one common share, for no additional consideration, for each RSU award held. If the vesting conditions are not met within 36 months of the date of grant, the RSUs are cancelled and of no further force and effect.	On January 1, 2012, the Board of Directors of Vista were granted a sum of 350,000 RSU awards. 300,000 of the January 1, 2012 grants vest under the same conditions as the 300,000 RSU awards granted on November 16, 2011 and 50,000 vest one year from the date of grant.