Gran Tierra Energy (GTE) 10-K 29 Feb 16 2015 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Feb. 23, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	GRAN TIERRA ENERGY INC.
Entity Central Index Key	1,273,441
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 0.8
Entity Common Stock, Shares Outstanding		287,129,518
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015

Consolidated Statements of Oper

Consolidated Statements of Operations and Retained Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
REVENUE AND OTHER INCOME
OIL AND NATURAL GAS SALES	$ 276,011	$ 559,398	$ 646,955
EXPENSES
Operating	75,565	89,753	91,223
Transportation	40,204	24,196	18,949
Depletion, depreciation and accretion	176,386	185,877	200,851
Asset impairment	323,918	265,126	2,000
General and administrative	32,353	51,249	41,115
Severance expenses	8,990	0	0
Equity tax	3,769	0	0
Foreign exchange gain	(17,242)	(39,535)	(18,693)
Financial instruments loss	2,027	4,722	0
Other loss	0	0	4,400
Other gain	(502)	(2,000)	0
Total expenses	645,468	579,388	339,845
INTEREST INCOME	1,369	2,856	2,174
(LOSS) INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(368,088)	(17,134)	309,284
Current	(15,383)	(92,865)	(157,126)
Deferred	115,442	(34,350)	28,865
Income tax expense	100,059	(127,215)	(128,261)
(LOSS) INCOME FROM CONTINUING OPERATIONS	(268,029)	(144,349)	181,023
Loss from discontinued operations, net of income taxes	0	(26,990)	(54,735)
NET INCOME (LOSS) AND COMPREHENSIVE INCOME (LOSS)	(268,029)	(171,339)	126,288
COMPREHENSIVE INCOME (LOSS)	$ (268,029)	$ (171,339)	$ 126,288
BASIC
LOSS (INCOME) FROM CONTINUING OPERATIONS (in dollars per share)	$ (0.94)	$ (0.51)	$ 0.64
LOSS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES (in dollars per share)	0	(0.09)	(0.19)
NET INCOME (LOSS) (in dollars per share)	(0.94)	(0.60)	0.45
DILUTED
(LOSS) INCOME FROM CONTINUING OPERATIONS (in dollars per share)	(0.94)	(0.51)	0.63
LOSS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES (in dollars per share)	0	(0.09)	(0.19)
NET INCOME (LOSS) (in dollars per share)	$ (0.94)	$ (0.60)	$ 0.44
WEIGHTED AVERAGE SHARES OUTSTANDING - BASIC	285,333,869	284,715,785	282,808,497
WEIGHTED AVERAGE SHARES OUTSTANDING - DILUTED	285,333,869	284,715,785	286,127,897

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 145,342	$ 331,848
Accounts receivable	29,217	83,227
Marketable securities	6,250	7,586
Inventory	19,056	17,298
Taxes receivable	28,635	15,843
Other current assets	5,940	7,836
Total Current Assets	234,440	463,638
Oil and Gas Properties (using the full cost method of accounting)
Proved	469,589	801,075
Unproved	310,771	316,856
Total Oil and Gas Properties	780,360	1,117,931
Other capital assets	8,633	11,013
Total Property, Plant and Equipment	788,993	1,128,944
Other Long-Term Assets
Taxes receivable	8,276	9,684
Other long-term assets	11,828	9,203
Goodwill	102,581	102,581
Total Other Long-Term Assets	122,685	121,468
Total Assets	1,146,118	1,714,050
Current Liabilities
Accounts payable and accrued liabilities	70,778	187,831
Foreign currency derivative	0	3,057
Taxes payable	1,067	25,412
Asset retirement obligation	2,146	8,026
Total Current Liabilities	73,991	224,326
Long-Term Liabilities
Deferred tax liabilities	34,592	176,364
Asset retirement obligation	31,078	27,786
Other long-term liabilities	4,815	8,889
Total Long-Term Liabilities	$ 70,485	$ 213,039
Commitments and Contingencies
Shareholders’ Equity
Common Stock (273,442,799 and 276,072,351 shares of Common Stock and 8,572,066 and 10,119,745 exchangeable shares, par value $0.001 per share, issued and outstanding as at December 31, 2015 and December 31, 2014, respectively)	$ 10,186	$ 10,190
Additional paid in capital	1,019,863	1,026,873
(Deficit) retained earnings	(28,407)	239,622
Total Shareholders’ Equity	1,001,642	1,276,685
Total Liabilities and Shareholders’ Equity	$ 1,146,118	$ 1,714,050

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common shares, par value (in dollars per share)	$ 0.001	$ 0.001
Common shares, issued	273,442,799	276,072,351
Common shares, outstanding	273,442,799	276,072,351
Exchangeable shares, issued	8,572,066	10,119,745
Exchangeable shares, outstanding	8,572,066	10,119,745

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income (loss)	$ (268,029)	$ (171,339)	$ 126,288
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Loss from discontinued operations, net of income taxes	0	26,990	54,735
Depletion, depreciation and accretion	176,386	185,877	200,851
Asset impairment	323,918	265,126	2,000
Deferred tax (recovery) expense	(115,442)	34,350	(28,865)
Non-cash stock-based compensation	2,091	5,451	8,002
Financial instruments loss	2,027	4,722	0
Unrealized foreign exchange gain	(8,380)	(30,941)	(16,103)
Cash settlement of foreign currency derivatives	(3,749)	4,661	0
Cash settlement of asset retirement obligation	(6,217)	(796)	(2,068)
Other loss	0	0	4,400
Other gain	(502)	(2,000)	0
Equity tax	0	(3,283)	(3,345)
Net change in assets and liabilities from operating activities of continuing operations	(39,798)	(97,866)	146,598
Net cash provided by operating activities of continuing operations	62,305	220,952	492,493
Net cash (used in) provided by operating activities of discontinued operations	0	(4,792)	31,064
Net cash provided by operating activities	62,305	216,160	523,557
Investing Activities
Decrease (increase) in restricted cash	465	(96)	(1,590)
Additions to property, plant and equipment	(156,639)	(391,526)	(345,865)
Changes in non-cash investing working capital	(76,844)	44,499	2,274
Proceeds from oil and gas properties	0	0	55,524
Net cash used in investing activities of continuing operations	(233,018)	(347,123)	(289,657)
Proceeds from sale of Argentina business unit, net of cash sold and transaction costs	0	42,755	0
Net cash used in investing activities of discontinued operations	0	(12,384)	(18,799)
Net cash provided by (used in) investing activities of discontinued operations	0	30,371	(18,799)
Net cash used in investing activities	(233,018)	(316,752)	(308,456)
Financing Activities
Repurchase of shares of Common Stock	(9,999)	0	0
Proceeds from issuance of shares of Common Stock	722	11,140	3,771
Net cash (used in) provided by financing activities	(9,277)	11,140	3,771
Foreign exchange loss on cash and cash equivalents	(6,516)	(7,500)	(2,696)
Net (decrease) increase in cash and cash equivalents	(186,506)	(96,952)	216,176
Cash and cash equivalents, beginning of year	331,848	428,800	212,624
Cash and cash equivalents, end of year	$ 145,342	$ 331,848	$ 428,800

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Share Capital [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]
Balance, beginning of year at Dec. 31, 2012		$ 7,986	$ 998,772	$ 284,673
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock		2,201
Exercise of stock options			1,570
Stock-based compensation			8,418
Repurchase of Common Stock		0	0
Net income (loss)	$ 126,288			126,288
Balance, end of year at Dec. 31, 2013	1,429,908	10,187	1,008,760	410,961
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock		$ 3
Exercise of stock options			11,137
Stock-based compensation			6,976
Repurchase of Common Stock			0
Net income (loss)	(171,339)			(171,339)
Balance, end of year at Dec. 31, 2014	1,276,685	$ 10,190	1,026,873	239,622
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock		0
Exercise of stock options			722
Stock-based compensation			2,263
Repurchase of Common Stock		(4)	(9,995)
Net income (loss)	(268,029)			(268,029)
Balance, end of year at Dec. 31, 2015	$ 1,001,642	$ 10,186	$ 1,019,863	$ (28,407)

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2015
Description of Business [Abstract]
Description of Business	Description of Business Gran Tierra Energy Inc., a Nevada corporation (the “Company” or “Gran Tierra”), is a publicly traded oil and gas company engaged in the acquisition, exploration, development and production of oil and natural gas properties. The Company’s principal business activity is in Colombia. The Company also has business activities in Peru and Brazil, and until June 25, 2014, had business activities in Argentina.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The Company believes that the information and disclosures presented are adequate to ensure the information presented is not misleading. Significant accounting policies are: Basis of consolidation These consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated. Discontinued operations On June 25, 2014, the Company completed the sale of its Argentina business unit and the discontinued operations criteria of Accounting Standards Codification ("ASC") 205-20, “ Discontinued Operations ”, were met. Therefore, the results of the Company’s Argentina business unit are reflected separately as loss from discontinued operations, net of income taxes, in the consolidated statement of operations for the two years ended December 31, 2014, on a line immediately after “Loss or income from continuing operations.” Additionally, cash flows of the Company’s Argentina business unit are reflected separately in the consolidated statement of cash flows for the two years ended December 31, 2014, as cash provided by or used in operating and investing activities of discontinued operations. See Note 3, “Discontinued Operations,” for additional disclosure. The Company did not recognize depletion, depreciation and accretion ("DD&A") expenses for the Argentina business unit subsequent to May 29, 2014, the date the assets were classified as held for sale. Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates made by management include: oil and natural gas reserves and related present value of future cash flows; depreciation, depletion, amortization and impairment (“DD&A”); impairment assessments of goodwill; timing of transfers from oil and gas properties not subject to depletion to the depletable base; asset retirement obligations; determining the value of the consideration transferred and the net identifiable assets acquired and liabilities assumed in connection with business combinations and determining goodwill; assessments of the likely outcome of legal and other contingencies; income taxes; stock-based compensation; and determining the fair value of foreign currency derivatives. Although management believes these estimates are reasonable, changes in facts and circumstances or discovery of new information may result in revised estimates and actual results may differ from these estimates. Cash and cash equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents. Restricted cash Restricted cash is included in other current assets and other long-term assets on the Company's balance sheet. Restricted cash comprises cash and cash equivalents pledged to secure letters of credit and to settle asset retirement obligations. Letters of credit currently secured by cash relate to work commitment guarantees contained in exploration contracts. Cash and claims to cash that are restricted as to withdrawal or use for other than current operations or are designated for expenditure in the acquisition or construction of long-term assets are excluded from the current asset classification. Allowance for doubtful accounts The Company estimates losses on receivables based on known uncollectible accounts, if any, and historical experience of losses incurred and accrues a reserve on a receivable when, based on the judgment of management, it is probable that a receivable will not be collected and the amount of the reserve may be reasonably estimated. The allowance for doubtful receivables was $ nil at December 31, 2015 , and 2014 . Marketable securities The Company acquired investments in marketable securities in connection with the sale of its Argentina business unit in 2014. Marketable securities are classified as trading securities, in accordance with ASC 320, “ Investments – Debt and Equity Securities ”, and are recorded in the consolidated balance sheet at fair value. The Company classifies trading securities as current or non-current based on the intent of management, the nature of the trading securities and whether they are readily available for use in current operations. Gains or losses on trading securities are recorded in the statement of operations as financial instruments gains or losses. Foreign currency derivatives The Company has, from time to time, purchased Colombian peso non-deliverable forward contracts for purposes of fixing exchange rates at which it will purchase or sell Colombian pesos to settle its income tax installment payments. The Company does not intend to issue or hold derivative financial instruments for speculative trading purposes. The Company records derivative instruments on the balance sheet as either an asset or liability measured at fair value. The accounting for changes in the fair value of a derivative instrument depends on the intended use of the derivative and the resulting designation, which is established at the inception of a derivative. Generally because of the short-term nature of the contracts and their limited use, the Company does not apply hedge accounting and changes in the fair value of those contracts are reflected in net income or loss as financial instrument gains or losses in the consolidated statement of operations. Cash settlements of the Company's derivative arrangements are classified as operating cash flows. The fair value of foreign currency derivatives is based on the estimated maturity value of the foreign exchange non-deliverable forward contracts, using applicable forward exchange rates. The most significant variable to the cash flow calculations is the estimation of forward foreign exchange rates. The resulting net future cash inflows or outflows at maturity of the contracts are the net value of the contract. Inventory Inventory consists of oil in tanks and third party pipelines and supplies and is valued at the lower of cost or market value. The cost of inventory is determined using the weighted average method. Oil inventories include expenditures incurred to produce, upgrade and transport the product to the storage facilities and include operating, depletion and depreciation expenses and cash royalties. Income taxes Income taxes are recognized using the liability method, whereby deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax base, and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. Valuation allowances are provided if, after considering available evidence, it is not more likely than not that some or all of the deferred tax assets will be realized. The tax benefit from an uncertain tax position is recognized when it is more likely than not, based on the technical merits of the position, that the position will be sustained on examination by the taxing authorities. Additionally, the amount of the tax benefit recognized is the largest amount of benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. In evaluating whether a tax position has met the more-likely-than-not recognition threshold, the Company presumes that the position will be examined by the appropriate taxing authority that has full knowledge of all relevant information. The Company recognizes potential penalties and interest related to unrecognized tax benefits as a component of income tax expense. Oil and gas properties The Company uses the full cost method of accounting for its investment in oil and natural gas properties as defined by the Securities and Exchange Commission (“SEC”). Under this method, the Company capitalizes all acquisition, exploration and development costs incurred for the purpose of finding oil and natural gas reserves, including salaries, benefits and other internal costs directly attributable to these activities. Costs associated with production and general corporate activities; however, are expensed as incurred. Interest costs related to unproved properties and properties under development are also capitalized to oil and natural gas properties. Separate cost centers are maintained for each country in which the Company incurs costs. The Company computes depletion of oil and natural gas properties on a quarterly basis using the unit-of-production method based upon production and estimates of proved reserve quantities. Future development costs related to properties with proved reserves are also included in the amortization base for computation of depletion. The costs of unproved properties are excluded from the amortization base until the properties are evaluated. The cost of exploratory dry wells is transferred to proved properties, and thus is subject to amortization, immediately upon determination that a well is dry in those countries where proved reserves exist. The Company performs a ceiling test calculation each quarter in accordance with SEC Regulation S-X Rule 4-10. In performing its quarterly ceiling test, the Company limits, on a country-by-country basis, the capitalized costs of proved oil and natural gas properties, net of accumulated depletion and deferred income taxes, to the estimated future net cash flows from proved oil and natural gas reserves discounted at 10% , net of related tax effects, plus the lower of cost or fair value of unproved properties included in the costs being amortized. If such capitalized costs exceed the ceiling, the Company will record a write-down to the extent of such excess as a non-cash charge to net income or loss. Any such write-down will reduce earnings in the period of occurrence and results in a lower DD&A rate in future periods. A write-down may not be reversed in future periods even though higher oil and natural gas prices may subsequently increase the ceiling. The Company calculates future net cash flows by applying the unweighted average of prices in effect on the first day of the month for the preceding 12-month period, adjusted for location and quality differentials. Such prices are utilized except where different prices are fixed and determinable from applicable contracts for the remaining term of those contracts. Unproved properties are not depleted pending the determination of the existence of proved reserves. Costs are transferred into the depletable base on an ongoing basis as the properties are evaluated and proved reserves are established or impairment is determined. Unproved properties are evaluated quarterly to ascertain whether impairment has occurred. This evaluation considers, among other factors, seismic data, requirements to relinquish acreage, drilling results and activity, remaining time in the commitment period, remaining capital plans, and political, economic, and market conditions. During any period in which factors indicate an impairment, the cumulative costs incurred to date for such property are transferred to the full cost pool and are then subject to depletion. For countries where a reserve base has not yet been established, the impairment is charged to earnings. In exploration areas, related seismic costs are capitalized in unproved property and evaluated as part of the total capitalized costs associated with a property. Seismic costs related to development projects are recorded in proved properties and therefore subject to depletion as incurred. Gains and losses on the sale or other disposition of oil and natural gas properties are not recognized, unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves of oil and natural gas attributable to a country. Asset retirement obligation The Company records an estimated liability for future costs associated with the abandonment of its oil and gas properties including the costs of reclamation of drilling sites. The Company records the fair value of a liability for a legal obligation to retire an asset in the period in which the liability is incurred with an offsetting increase to the related oil and gas properties. The fair value of an asset retirement obligation is measured by reference to the expected future cash outflows required to satisfy the retirement obligation discounted at the Company’s credit-adjusted risk-free interest rate. Accretion expense is recognized over time as the discounted liabilities are accreted to their expected settlement value, while the asset retirement cost is amortized over the estimated productive life of the related assets. The accretion of the asset retirement obligation and amortization of the asset retirement cost are included in DD&A. If estimated future costs of an asset retirement obligation change, an adjustment is recorded to both the asset retirement obligation and oil and gas properties. Revisions to the estimated asset retirement obligation can result from changes in retirement cost estimates, revisions to estimated inflation rates and changes in the estimated timing of abandonment. Other capital assets Other capital assets, including additions and replacements, are recorded at cost upon acquisition and include furniture, fixtures and leasehold improvement, computer equipment and automobiles. Depreciation is provided using the declining-balance method at a 30% annual rate for furniture and fixtures, computer equipment and automobiles. Leasehold improvements are depreciated on a straight-line basis over the shorter of the estimated useful life and the term of the related lease. The cost of repairs and maintenance is charged to expense as incurred. Goodwill Goodwill represents the excess of the aggregate of the consideration transferred over the net identifiable assets acquired and liabilities assumed. The Company assesses qualitative factors annually, or more frequently if necessary, to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount and whether it is necessary to perform the two-step goodwill impairment test. The impairment test requires allocating goodwill and certain other assets and liabilities to assigned reporting units. The fair value of each reporting unit is estimated and compared with the net book value of the reporting unit. If the estimated fair value of the reporting unit is less than the net book value, including goodwill, then the goodwill is written down to the implied fair value of the goodwill through a charge to expense. Because quoted market prices are not available for the Company’s reporting units, the fair values of the reporting units are estimated based upon estimated future cash flows of the reporting unit. The Company recorded $87.6 million of goodwill in relation to the acquisition of Solana Resources Limited (“Solana”) in 2008 and $15.0 million of goodwill in relation to the Argosy Energy International L.P. acquisition in 2006. The goodwill relates entirely to the Colombia reportable segment. The Company performed a quantitative assessment of goodwill at December 31, 2015 , and based on this assessment, no impairment of goodwill was identified. Revenue recognition Revenue from the production of oil and natural gas is recognized when the customer has taken title and has assumed the risks and rewards of ownership, prices are fixed or determinable, the sale is evidenced by a contract and collection of the revenue is reasonably assured. In Colombia, the sales point for the Company's sales varies depending on the delivery point but includes the Port of Tumaco on the Pacific coast of Colombia, the purchaser's facilities and when oil is loaded into a truck at Gran Tierra's loading facility or an export tanker. In Brazil, the sales point is either the Petróleo Brasileiro S.A station or the purchaser's facility. Revenue represents the Company’s share and is recorded net of royalty payments to governments and other mineral interest owners. Stock-based compensation The Company grants time-vested restricted stock units ("RSUs") to officers, employees and consultants. RSUs entitle the holder to receive, at the option of the Company, either the underlying number of shares of the Company's Common Stock upon vesting of such shares or a cash payment equal to the value of the underlying shares. The Company's practice is to settle RSUs in cash and, therefore, RSUs are accounted for as liability instruments. Compensation expense for RSUs granted is based on the estimated fair value, which is determined using the closing share price, at each reporting date, and the expense, net of estimated forfeitures, is recognized over the requisite service period using the accelerated method, with a corresponding change to liabilities. An adjustment is made to compensation expense for any difference between the estimated forfeitures and the actual forfeitures. Additionally, the Company grants options to purchase shares of Common Stock to certain directors, officers, employees and consultants. The Company follows the fair-value based method of accounting for stock options granted. Compensation expense for options granted is based on the estimated fair value, using the Black-Scholes option pricing model, at the time of grant and the expense, net of estimated forfeitures, is recognized over the requisite service period using the accelerated method. An adjustment is made to compensation expense for any difference between the estimated forfeitures and the actual forfeitures . The Company uses historical data to estimate expected term used in the Black-Scholes option pricing model, option exercises and employee departure behavior. Expected volatilities used in the fair value estimate are based on historical volatility of the Company’s shares. The risk-free rate for periods within the expected term of the stock options is based on the U.S. Treasury yield curve in effect at the time of grant. Stock-based compensation expense relating to RSUs and stock options is capitalized as part of oil and natural gas properties or expensed as part of operating expenses or general and administrative (“G&A”) expenses, as appropriate. Foreign currency translation The functional currency of the Company, including its subsidiaries, is the United States dollar. Monetary items are translated into the reporting currency at the exchange rate in effect at the balance sheet date and non-monetary items are translated at historical exchange rates. Revenue and expense items are translated in a manner that produces substantially the same reporting currency amounts that would have resulted had the underlying transactions been translated on the dates they occurred. Depreciation or amortization of assets is translated at the historical exchange rates similar to the assets to which they relate. Gains and losses resulting from foreign currency transactions, which are transactions denominated in a currency other than the entity’s functional currency, are recognized in net income or loss. Net income or loss per share Basic net income or loss per share is calculated by dividing net income or loss attributable to common shareholders by the weighted average number of shares of Common Stock and exchangeable shares issued and outstanding during each period. Diluted net income or loss per share is calculated by adjusting the weighted average number of shares of Common Stock and exchangeable shares outstanding for the dilutive effect, if any, of share equivalents. The Company uses the treasury stock method to determine the dilutive effect. This method assumes that all Common Stock equivalents have been exercised at the beginning of the period (or at the time of issuance, if later), and that the funds obtained thereby were used to purchase shares of Common Stock of the Company at the volume weighted average trading price of shares of Common Stock during the period. Recently Issued Accounting Pronouncements Revenue from Contracts with Customers In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers ". The ASU creates a single source of revenue guidance for all companies in all industries and requires revenue recognition to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 sets forth a new revenue recognition model that requires identifying the contract, identifying the performance obligations, determining the transaction price, allocating the transaction price to performance obligations and recognizing the revenue upon satisfaction of performance obligations. The amendments in the ASU can be applied either retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the update recognized at the date of the initial application along with additional disclosures. In August 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers - Deferral of the Effective Date". The ASU defers the effective date of the new revenue recognition model by one year. As a result, the guidance will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. The Company is currently assessing the impact the new standard will have on its consolidated financial position, results of operations, cash flows, and disclosure. Simplifying the Measurement of Inventory In July 2015, the FASB issued ASU 2015-11, “Simplifying the Measurement of Inventory". The ASU provides guidance for the subsequent measurement of inventory and requires that inventory that is measured using average cost be measured at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The ASU will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The implementation of this update is not expected to materially impact the Company’s consolidated financial position, results of operations or cash flows or disclosure. Simplifying the Accounting for Measurement-Period Adjustments In September 2015, the FASB issued ASU 2015-16, "Simplifying the Accounting for Measurement-Period Adjustments". ASU 2015-16 requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. ASU 2015-16 is effective for fiscal years and interim reporting periods within those fiscal years, beginning after December 15, 2015. Prospective adoption is required. This ASU is not expected to have a material impact on the Company's consolidated financial position, results of operations or cash flows or disclosure. Balance Sheet Classification of Deferred Taxes In November 2015, the FASB issued ASU 2015-17, "Balance Sheet Classification of Deferred Taxes". ASU 2015-17 requires that deferred tax liabilities and assets be classified as long-term in a classified balance sheet . ASU 2015-17 is effective for annual reporting periods and interim reporting periods within those annual reporting periods, beginning after December 15, 2016. Early application is permitted. The amendments in this ASU may be applied either prospectively to all deferred tax liabilities and assets or retrospectively to all periods presented. The Company implemented this update retrospectively in its consolidated financial statements for the year ended December 31, 2015, so that the balance sheet is presented on a comparable basis. Deferred tax liabilities and assets of $1.0 million and $1.6 million , respectively, have been reclassified from current to long-term in the Company's December 31, 2014 balance sheet. The implementation of this update did not impact the Company’s consolidated results of operations or cash flows. Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, "Recognition and Measurement of Financial Assets and Financial Liabilities". ASU 2016-01 addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 is effective for annual reporting periods and interim reporting periods within those annual reporting periods, beginning after December 15, 2017. This ASU is not expected to have a material impact on the Company's consolidated financial position, results of operations or cash flows or disclosure.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations On June 25, 2014, the Company, through several of its indirect subsidiaries (the “Selling Subsidiaries”), sold its Argentina business unit to Madalena Energy Inc. ("Madalena") for aggregate consideration of $69.3 million , comprising $55.4 million in cash and $13.9 million in Madalena shares. Accordingly, the results of the Company’s Argentina business unit are classified as “Loss from discontinued operations, net of income taxes” on the consolidated statements of operations for the two years ended December 31, 2014. Additionally, cash flows of the Company’s Argentina business unit are presented separately in the consolidated statement of cash flows for the two years ended December 31, 2014, as cash provided by or used in operating and investing activities of discontinued operations. Revenue and other income and loss from discontinued operations, net of income taxes, for the two years ended December 31, 2014, were as follows: Year Ended December 31, (Thousands of U.S. Dollars) 2014 2013 Revenue and other income $ 31,985 $ 74,514 Loss income from operations of discontinued operations before income taxes $ (6,252 ) $ (47,448 ) Income tax expense (1,458 ) (7,287 ) Loss from operations of discontinued operations (7,710 ) (54,735 ) Loss on sale before income taxes (18,235 ) — Income tax expense (1,045 ) — Loss on sale (19,280 ) — Loss from discontinued operations, net of income taxes $ (26,990 ) $ (54,735 ) Results from discontinued operations before income taxes for the year ended December 31, 2014, were calculated to the date of sale of June 25, 2014. The Company classified the Argentina business unit as held for sale at May 29, 2014. In the year ended December 31, 2013, the Company recorded a ceiling test impairment loss of $30.8 million in the Company's Argentina cost center as a result of deferred investment and inconclusive waterflood results.

Segment and Geographic Reportin

Segment and Geographic Reporting	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment and Geographic Reporting	Segment and Geographic Reporting The Company is primarily engaged in the exploration and production of oil and natural gas. The Company’s reportable segments are Colombia, Peru and Brazil based on geographic organization. The All Other category represents the Company’s corporate activities. The Company evaluates reportable segment performance based on income or loss from continuing operations before income taxes. The following tables present information on the Company’s reportable segments and other activities: Year Ended December 31, 2015 (Thousands of U.S. Dollars, except per unit of sales amounts) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 269,035 $ — $ 6,976 $ — $ 276,011 Interest income 294 2 218 855 1,369 DD&A expenses 167,701 789 6,183 1,713 176,386 DD&A - per unit of sales 25.90 — 32.66 — 26.47 Asset impairment 235,069 41,916 46,933 — 323,918 General and administrative 9,805 3,800 2,708 16,040 32,353 Loss from continuing operations before income taxes (238,463 ) (51,675 ) (54,968 ) (22,982 ) (368,088 ) Segment capital expenditures 87,723 50,419 19,989 1,095 159,226 Year Ended December 31, 2014 (Thousands of U.S. Dollars, except per unit of sales amounts) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 532,196 $ — $ 27,202 $ — $ 559,398 Interest income 569 1 1,604 682 2,856 DD&A expenses 174,063 690 9,932 1,192 185,877 DD&A - per unit of sales 27.07 — 30.09 — 27.49 Asset impairment — 265,126 — — 265,126 General and administrative 19,431 6,448 3,698 21,672 51,249 Income (loss) from continuing operations before income taxes 279,924 (274,207 ) 5,921 (28,772 ) (17,134 ) Segment capital expenditures 214,928 174,158 24,278 2,868 416,232 Year Ended December 31, 2013 (Thousands of U.S. Dollars, except per unit of sales amounts) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 624,410 $ — $ 22,545 $ — $ 646,955 Interest income 623 27 909 615 2,174 DD&A expenses 184,697 362 14,761 1,031 200,851 DD&A - per unit of sales 27.23 — 61.75 — 28.60 Asset impairment — — 2,000 — 2,000 General and administrative 16,996 5,524 2,231 16,364 41,115 Income (loss) from continuing operations before income taxes 336,179 (7,067 ) (2,650 ) (17,178 ) 309,284 Segment capital expenditures (1) 188,547 82,954 23,039 775 295,315 (1) In 2013, segment capital expenditures are net of proceeds of: $54.0 million relating to termination of a farm-in agreement in Brazil; and $1.5 million relating to the Company's sale of its 15% working interest in the Mecaya Block in Colombia (Note 6). As at December 31, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Property, plant and equipment $ 574,351 $ 95,069 $ 115,552 $ 4,021 $ 788,993 Goodwill 102,581 — — — $ 102,581 All other assets 93,479 21,111 2,236 137,718 $ 254,544 Total Assets $ 770,411 $ 116,180 $ 117,788 $ 141,739 $ 1,146,118 As at December 31, 2014 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Property, plant and equipment $ 888,822 $ 87,028 $ 148,457 $ 4,637 $ 1,128,944 Goodwill 102,581 — — — $ 102,581 All other assets 157,549 40,613 14,724 269,639 $ 482,525 Total Assets $ 1,148,952 $ 127,641 $ 163,181 $ 274,276 $ 1,714,050 In the year ended December 31, 2015, the Company had four significant customers which accounted for 43% , 15% , 13% and 12% of the Company's consolidated oil and natural gas sales. In the years ended December 31, 2014 and 2013, the Company had two significant customers which accounted for 52% and 32% , and 46% and 42% , respectively, of the Company's consolidated oil and natural gas sales.

Accounts Receivable and Invento

Accounts Receivable and Inventory	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Accounts Receivable and Inventory	Accounts Receivable and Inventory Accounts Receivable As at December 31, (Thousands of U.S. Dollars) 2015 2014 Trade $ 26,924 $ 80,058 Other 2,293 3,169 $ 29,217 $ 83,227 Inventory At December 31, 2015 , oil and supplies inventories were $17.8 million and $1.3 million , respectively ( December 31, 2014 - $15.2 million and $2.1 million , respectively). In the year ended December 31, 2015 , the Company recorded oil inventory impairment of $2.6 million ( year ended December 31, 2014 - $ nil , year ended December 31, 2013 - $ nil ) related to lower oil prices (Note 6).

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment As at December 31, (Thousands of U.S. Dollars) 2015 2014 Oil and natural gas properties Proved $ 1,998,330 $ 1,876,371 Unproved 310,771 316,856 2,309,101 2,193,227 Other 28,342 27,287 2,337,443 2,220,514 Accumulated depletion, depreciation and impairment (1,548,450 ) (1,091,570 ) $ 788,993 $ 1,128,944 In the year ended December 31, 2015, the Company recorded ceiling test impairment losses of $232.4 million in its Colombia cost center, and $46.9 million in its Brazil cost center, related to lower oil prices. The Company follows the full cost method of accounting for its oil and gas properties. Under this method, the net book value of properties on a country-by-country basis, less related deferred income taxes, may not exceed a calculated “ceiling”. The ceiling is the estimated after tax future net revenues from proved oil and gas properties, discounted at 10% per year. In calculating discounted future net revenues, oil and natural gas prices are determined using the average price during the 12 months period prior to the ending date of the period covered by the balance sheet, calculated as an unweighted arithmetic average of the first-day-of-the month price for each month within such period for that oil and natural gas. That average price is then held constant, except for changes which are fixed and determinable by existing contracts. Therefore, ceiling test estimates are based on historical prices discounted at 10% per year and it should not be assumed that estimates of future net revenues represent the fair market value of the Company's reserves. In the year ended December 31, 2015, the Company recorded an impairment loss in its Peru cost center of $41.9 million related to costs incurred on Block 95. On February 19, 2015, the Company made the decision to cease all further development expenditures on the Bretaña Field on Block 95 other than what is necessary to maintain tangible asset integrity and security. In the year ended December 31, 2014, the Company recorded an impairment loss in its Peru cost center of $265.1 million related to costs incurred on Block 95. In the year ended December 31, 2013, the Company recorded a ceiling test impairment loss of $2.0 million in its Brazil cost center as a result of lower realized prices and increased operating costs. Asset impairment for the three years ended December 31, 2015 , was follows: (Thousands of U.S. Dollars) Year Ended December 31, 2015 2014 2013 Impairment of oil and gas properties $ 321,285 $ 265,126 $ 2,000 Impairment of inventory (Note 5) 2,633 — — $ 323,918 $ 265,126 $ 2,000 Depletion and depreciation expense on property, plant and equipment for the year ended December 31, 2015 , was $177.9 million ( year ended December 31, 2014 - $187.9 million ; year ended December 31, 2013 - $194.2 million ). A portion of depletion and depreciation expense was recorded as inventory in each year and adjusted for inventory changes. In 2013, the Company received a net payment of $54.0 million (before income taxes) from a third party in connection with the termination of a farm-in agreement in Brazil and $1.5 million relating to a sale of its working interest of a block in Colombia. The Company successfully bid on three blocks in the 2013 Brazil Bid Round 11 administered by Brazil's Agência Nacional de Petróleo, Gás Natural e Biocombustíveis ("ANP") and, in 2013, paid a signature bonus of $14.4 million upon finalization of the concession agreements. Unproved oil and natural gas properties consist of exploration lands held in Colombia, Peru and Brazil. As at December 31, 2015 , the Company had $147.5 million ( December 31, 2014 - $170.5 million ) of unproved assets in Colombia, $94.2 million ( December 31, 2014 - $85.7 million ) of unproved assets in Peru, and $69.1 million ( December 31, 2014 - $60.7 million ) of unproved assets in Brazil for a total of $310.8 million ( December 31, 2014 - $316.9 million ). Unproved oil and natural gas properties are being held for their exploration value and are not being depleted pending determination of the existence of proved reserves. Gran Tierra will continue to assess the unproved properties over the next several years as proved reserves are established and as exploration warrants whether or not future areas will be developed. The Company expects that approximately 60% of costs not subject to depletion at December 31, 2015 , will be transferred to the depletable base within the next five years and the remainder in the next five to 10 years. The following is a summary of Gran Tierra’s oil and natural gas properties not subject to depletion as at December 31, 2015 : Costs Incurred in (Thousands of U.S. Dollars) 2015 2014 2013 Prior to 2013 Total Acquisition costs - Colombia $ — $ — $ — $ 67,597 $ 67,597 Acquisition costs - Peru — — — 21,147 21,147 Acquisition costs - Brazil — — — 35,525 35,525 Exploration costs - Colombia 11,151 35,952 20,103 12,697 79,903 Exploration costs - Peru 8,515 31,750 7,301 25,469 73,035 Exploration costs - Brazil 10,639 8,911 14,779 (765 ) 33,564 Total oil and natural gas properties not subject to depletion $ 30,305 $ 76,613 $ 42,183 $ 161,670 $ 310,771

Share Capital

Share Capital	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Share Capital	Share Capital The Company’s authorized share capital consists of 595,000,002 shares of capital stock, of which 570 million are designated as Common Stock, par value $0.001 per share, 25 million are designated as Preferred Stock, par value $0.001 per share, and two shares are designated as special voting stock, par value $0.001 per share. As at December 31, 2015 , outstanding share capital consists of 273,442,799 shares of Common Stock of the Company, 4,933,177 exchangeable shares of Gran Tierra Exchangeco Inc., (the "Exchangeco exchangeable shares") and 3,638,889 exchangeable shares of Gran Tierra Goldstrike Inc. (the "Goldstrike exchangeable shares"). The Exchangeco exchangeable shares were issued upon the acquisition of Solana. The Goldstrike exchangeable shares were issued upon the business combination between Gran Tierra Energy Inc., an Alberta corporation, and Goldstrike, Inc., which is now the Company. The redemption date for the Exchangeco exchangeable shares and the Goldstrike exchangeable shares is a date to be established by the applicable Board of Directors. On July 22, 2015, the Company announced that it intended to implement a new share repurchase program (the “2015 Program”) through the facilities of the Toronto Stock Exchange ("TSX"), the NYSE MKT and eligible alternative trading platforms in Canada and the United States. The Company received regulatory approval from the TSX to commence the 2015 Program on July 27, 2015. The Company is able to purchase at prevailing market prices up to 13,831,866 shares of Common Stock, representing 4.98% of the issued and outstanding shares of Common Stock as of July 21, 2015. Shares purchased pursuant to the 2015 Program will be canceled. The 2015 Program will expire on July 29, 2016, or earlier if the 4.98% share maximum is reached. The 2015 Program may be terminated by the Company at any time, subject to compliance with regulatory requirements. As such, there can be no assurance regarding the total number of shares that may be repurchased under the 2015 Program. During 2015, the Company repurchased 4.6 million shares at an average price of $2.19 for total proceeds of $10.0 million . Shares of Common Stock Exchangeable Shares of Gran Tierra Exchangeco Inc. Exchangeable Shares of Gran Tierra Goldstrike Inc. Balance, December 31, 2014 276,072,351 5,595,118 4,524,627 Options exercised 390,000 — — Shares repurchased and canceled (4,567,136 ) — — Exchange of exchangeable shares 1,547,595 (661,857 ) (885,738 ) Shares canceled (11 ) (84 ) — Balance, December 31, 2015 273,442,799 4,933,177 3,638,889 The holders of shares of Common Stock are entitled to one vote for each share on all matters submitted to a stockholder vote and are entitled to share in all dividends that the Company’s Board of Directors, in its discretion, declares from legally available funds. The holders of Common Stock have no pre-emptive rights, no conversion rights, and there are no redemption provisions applicable to the shares. Holders of exchangeable shares have substantially the same rights as holders of shares of Common Stock. Each exchangeable share is exchangeable into one share of Common Stock of the Company. Restricted Stock Units and Stock Options In accordance with the 2007 Equity Incentive Plan, the Company’s Board of Directors is authorized to issue options or other rights to acquire shares of the Company’s Common Stock. On June 27, 2012, the shareholders of Gran Tierra approved an amendment to the Company’s 2007 Equity Incentive Plan, which increased the Common Stock available for issuance thereunder from 23,306,100 shares to 39,806,100 shares. The Company grants time-vested RSUs to certain officers, employees and consultants. RSUs entitle the holder to receive, at the option of the Company, either the underlying number of shares of the Company's Common Stock upon vesting of such shares or a cash payment equal to the value of the underlying shares. The Company's practice is to settle RSUs in cash. Additionally, the Company grants options to purchase shares of Common Stock to certain directors, officers, employees and consultants. Each option permits the holder to purchase one share of Common Stock at the stated exercise price. At the time of grant, the exercise price equals the market price. Options and RSUs generally vest over three years. The Company does not expect to repurchase any shares in the open market to settle any such exercises. The term of options granted starting May 2013 is five years or three months after the grantee’s end of service to the Company, whichever occurs first. Options granted prior to May 2013 continue to have a term of ten years or three months after the grantee’s end of service to the Company, whichever occurs first. Once an RSU is vested, it is immediately settled and considered to be at the end of its term. The fair value of each stock option award is estimated on the date of grant using the Black-Scholes option pricing model based on assumptions noted in the following table: Year Ended December 31, 2015 2014 2013 Dividend yield (per share) Nil Nil Nil Volatility 46% to 50% 39% to 42% 42% to 54% Weighted average volatility 48 % 41 % 53 % Risk-free interest rate 1.20% to 1.68% 0.78% to 1.45% 0.3% to 0.7% Expected term 4-5 years 4-5 years 4-5 years The following table provides information about RSU and stock option activity for the year ended December 31, 2015 : RSUs Options Number of Outstanding Share Units Number of Outstanding Options Weighted Average Exercise Price $/Option Balance, December 31, 2014 1,236,963 13,790,220 $ 5.93 Granted 1,041,450 5,346,260 3.08 Exercised (531,012 ) (390,000 ) 1.85 Forfeited (731,944 ) (1,394,445 ) (5.63 ) Expired — (4,500,478 ) (6.78 ) Balance, December 31, 2015 1,015,457 12,851,557 $ 4.60 Exercisable, at December 31, 2015 7,784,678 $ 5.17 Vested, or expected to vest, at December 31, 2015, through the life of the options 12,494,309 $ 4.63 For the year ended December 31, 2015 , 390,000 shares of Common Stock were issued for cash proceeds of $0.7 million upon the exercise of 390,000 stock options ( 2014 – 3,029,853 ; 2013 – 1,306,317 ). For the year ended December 31, 2015 , the Company paid $1.7 million to cash settle RSUs ( 2014 - $3.4 million and 2013 - $ nil ). At December 31, 2015 , the weighted average remaining contractual term of outstanding stock options was 3.3 years and of exercisable stock options was 2.7 years. The weighted average grant date fair value for options granted in the year ended December 31, 2015 , was $1.24 ( 2014 - $2.47 ; 2013 - $2.62 ). The weighted average grant date fair value for options vested in the year ended December 31, 2015 , was $2.38 ( 2014 - $3.63 ; 2013 - $3.94 ). The total fair value of stock options vested during year ended December 31, 2015 , was $6.8 million ( 2014 - $12.4 million ; 2013 - $12.4 million ). The amounts recognized for stock-based compensation were as follows: (Thousands of U.S. Dollars) Year Ended December 31, 2015 2014 2013 Compensation costs for stock options $ 2,263 $ 6,976 $ 8,418 Compensation costs for RSUs 629 2,559 2,936 2,892 9,535 11,354 Less: Stock-based compensation costs capitalized (159 ) (1,815 ) (2,436 ) Stock-based compensation costs expensed $ 2,733 $ 7,720 $ 8,918 At December 31, 2015 , there was $3.9 million ( December 31, 2014 - $4.8 million ) of unrecognized compensation cost related to unvested stock options and RSUs which is expected to be recognized over a weighted average period of 1.5 years. The weighted-average remaining contractual term of options vested, or expected to vest, at December 31, 2015 was 3.2 years. Weighted Average Shares Outstanding Year Ended December 31, 2015 2014 2013 Weighted average number of common and exchangeable shares outstanding 285,333,869 284,715,785 282,808,497 Shares issuable pursuant to stock options — — 12,041,260 Shares assumed to be purchased from proceeds of stock options — — (8,721,860 ) Weighted average number of diluted common and exchangeable shares outstanding 285,333,869 284,715,785 286,127,897 For the year ended December 31, 2015 , 13,432,287 options, on a weighted average basis, ( 2014 - 15,621,890 options; 2013 - 4,217,082 options) were excluded from the diluted loss per share calculation as the options were anti-dilutive.

Asset Retirement Obligation

Asset Retirement Obligation	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation [Abstract]
Asset Retirement Obligation	Asset Retirement Obligation Changes in the carrying amounts of the asset retirement obligation associated with the Company’s oil and natural gas properties were as follows: Year Ended December 31, (Thousands of U.S. Dollars) 2015 2014 Balance, beginning of year $ 35,812 $ 21,973 Settlements (6,317 ) (1,137 ) Liability incurred 1,556 11,956 Liabilities associated with the Argentina business unit sold — (10,170 ) Accretion 1,313 1,406 Revisions in estimated liability 860 11,784 Balance, end of year $ 33,224 $ 35,812 Asset retirement obligation - current $ 2,146 $ 8,026 Asset retirement obligation - long-term 31,078 27,786 Balance, end of year $ 33,224 $ 35,812 For the year ended December 31, 2015 , settlements included cash payments of $6.2 million with the balance in accounts payable and accrued liabilities at December 31, 2015 . Revisions in estimated liabilities relate primarily to changes in estimates of asset retirement costs and include, but are not limited to, revisions of estimated inflation rates, changes in property lives and the expected timing of settling the asset retirement obligation. During the year ended December 31, 2014, estimated asset retirement liabilities were increased by $7.6 million to reflect accelerated revised outcome probabilities and their timing as a result of the decision to cease all further development expenditures on the Bretaña Field on Block 95 in Peru other than what is necessary to maintain tangible asset integrity and security. At December 31, 2015 , the fair value of assets that are legally restricted for purposes of settling asset retirement obligations was $2.9 million ( December 31, 2014 - $2.0 million ). These assets are accounted for as restricted cash and included in other current assets and other long-term assets on the Company's balance sheet.

Taxes

Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Taxes	Taxes The income tax expense reported differs from the amount computed by applying the U.S. statutory rate to income or loss from continuing operations before income taxes for the following reasons: Year Ended December 31, (Thousands of U.S. Dollars) 2015 2014 2013 (Loss) income from continuing operations before income taxes United States $ (14,061 ) $ (19,744 ) $ (13,566 ) Foreign (354,027 ) 2,610 322,850 (368,088 ) (17,134 ) 309,284 35 % 35 % 35 % Income tax (recovery) expense from continuing operations expected (128,831 ) (5,997 ) 108,249 Foreign currency translation adjustments (187 ) (6,520 ) (7,185 ) Impact of foreign taxes (1) (13,087 ) 27,910 (3,596 ) Other local taxes 2,354 4,433 3,673 Stock-based compensation 919 2,232 2,724 Increase in valuation allowance 37,691 94,922 21,423 Non-deductible third party royalty in Colombia 3,416 9,116 11,073 Other permanent differences (2) (2,334 ) 1,119 (8,100 ) Total income tax (recovery) expense from continuing operations $ (100,059 ) $ 127,215 $ 128,261 Current income tax expense from continuing operations United States $ 1,070 $ 1,260 $ 1,250 Foreign 14,313 91,605 155,876 15,383 92,865 157,126 Deferred income tax (recovery) expense from continuing operations Foreign (3) (115,442 ) 34,350 (28,865 ) Total income tax (recovery) expense from continuing operations $ (100,059 ) $ 127,215 $ 128,261 (1) Impact of foreign taxes in the rate reconciliation are tax effected at the 35% statutory rate and for the years ended December 31, 2015 and 2014, included $11.8 million and $28.1 million , respectively, in Colombia. (2) Other permanent differences in the rate reconciliation are tax effected at the 35% statutory rate. For the year ended December 31, 2013, these differences included $7.4 million of tax basis and loss adjustments, $5.0 million of which were offset by changes in the valuation allowance. (3) The deferred tax recovery for the year ended December 31, 2015, included $91.7 million associated with the ceiling test impairment loss in Colombia. In the fourth quarter of 2014, Congressional authorities in Colombia and Peru enacted new legislation containing tax rate changes effective January 1, 2015. In Colombia, the CREE tax that was previously introduced as a temporary measure was made permanent and an additional surtax was introduced for 2015 to 2018 fiscal periods , resulting in an increase of the Colombian deferred tax liability of approximately $31.0 million . Accordingly, the CREE surtax rate during this period will be as follows: 2015: 5% ; 2016: 6% ; 2017: 8% and 2018: 9% . These increases will result in a consolidated income tax, CREE tax and CREE surtax rate of: 39% for 2015; 40% for 2016; 42% for 2017; and 43% for 2018. Under current legislation, the consolidated rate is set to revert to 34% in 2019 and onwards. In Peru, the legislation contained scheduled reductions to the income tax rate in 2015 through 2019. The tax rates applied to the calculation of deferred income taxes have been adjusted to reflect these changes. As at December 31, (Thousands of U.S. Dollars) 2015 2014 Deferred Tax Assets Tax benefit of operating loss carryforwards $ 56,015 $ 51,248 Tax basis in excess of book basis 139,012 108,120 Foreign tax credits and other accruals 22,674 20,369 Tax benefit of capital loss carryforwards 30,799 29,984 Deferred tax assets before valuation allowance 248,500 209,721 Valuation allowance (245,259 ) (207,568 ) 3,241 2,153 Deferred Tax Liabilities 34,592 176,364 Net Deferred Tax Liabilities $ (31,351 ) $ (174,211 ) Undistributed earnings of foreign subsidiaries as of December 31, 2015 , were considered to be permanently reinvested. A determination of the amount of unrecognized deferred tax liability on these undistributed earnings is not practicable. As at December 31, 2015 , the Company had operating loss carryforwards of $178.7 million ( December 31, 2014 - $167.0 million ) and capital loss carryforwards of $228.1 million ( December 31, 2014 – $232.2 million ) before valuation allowance. Of these operating loss and capital loss carryforwards, $355.9 million ( December 31, 2014 - $356.1 million ) were losses generated by the foreign subsidiaries of the Company. In certain jurisdictions, the operating loss carryforwards expire between 2015 and 2035 and the capital loss carryforwards expire between 2016 and 2020, while certain other jurisdictions allow operating and capital losses to be carried forward indefinitely. The valuation allowance increased by $37.7 million during the year ended December 31, 2015 . The change in the valuation allowance was primarily due to impairment losses recorded in Peru and Brazil and an increased corporate tax rate in Canada, partially offset by foreign currency translation adjustments. Also, the Company continues to incur losses in the U.S., Peru, Brazil and Canada. These losses are fully offset by a valuation allowance as their recognition does not meet the “more likely than not” threshold. As at December 31, 2015 , the total amount of Gran Tierra’s unrecognized tax benefit related to continuing operations was $2.2 million ( December 31, 2014 - $3.3 million ; December 31, 2013 - $2.9 million ), which if recognized would affect the Company’s effective tax rate. To the extent interest and penalties may be assessed by taxing authorities on any underpayment of income tax, such amounts have been accrued and are classified as a component of income taxes in the consolidated statement of operations. As at December 31, 2015 , the amount of interest and penalties on the unrecognized tax benefit included in current income tax liabilities in the consolidated balance sheet was approximately $1.4 million ( December 31, 2014 - $2.0 million ). Interest and penalties on the unrecognized tax benefit included in income tax expense from continuing operations for the year ended December 31, 2015 was a recovery of $0.6 million ( 2014 - $0.4 million ; 2013 - a recovery of $2.1 million ). The Company had no other material interest or penalties included in the consolidated statement of operations for the three years ended December 31, 2015 , respectively. Changes in the Company's unrecognized tax benefit relating to loss or income from continuing operations are as follows: Year Ended December 31, 2015 2014 2013 (Thousands of U.S. Dollars) Unrecognized tax benefit relating to loss or income from continuing operations, beginning of year $ 3,300 $ 2,900 $ 5,900 Increases for positions relating to prior year — 500 — Decreases for positions relating to prior year (800 ) (100 ) (3,000 ) Decreases due to lapse of statute of limitations (300 ) — — Unrecognized tax benefit relating to loss or income from continuing operations, end of year $ 2,200 $ 3,300 $ 2,900 The Company and its subsidiaries file income tax returns in U.S. federal and state jurisdictions and certain other foreign jurisdictions. The Company is potentially subject to income tax examinations for the tax years 2008 through 2015 in certain jurisdictions. The Company does not anticipate any material changes to the unrecognized tax benefit disclosed above within the next twelve months. On December 23, 2014, the Colombian Congress passed a law which imposes an equity tax levied on Colombian operations for 2015, 2016 and 2017. The equity tax is calculated based on a legislated measure, which is based on the Company’s Colombian legal entities' balance sheet equity for tax purposes at January 1, 2015. This measure is subject to adjustment for inflation in future years. The equity tax rates for January 1, 2015, 2016 and 2017, are 1.15% , 1% and 0.4% , respectively. The legal obligation for each year's equity tax liability arises on January 1 of each year; therefore, the Company recognized the annual amount of $3.8 million for the equity tax expense in the consolidated statement of operations for the year ended December 31, 2015. This amount was paid in May and September 2015 and at December 31, 2015 , accounts payable included $ nil ( December 31, 2014 - $ nil ).

Accounts Payable and Accrued Li

Accounts Payable and Accrued Liabilities	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Accounts Payable and Accrued Liabilities	Accounts Payable and Accrued Liabilities As at December 31, (Thousands of U.S. Dollars) 2015 2014 Trade $ 54,402 $ 148,998 Royalties 2,066 10,788 VAT and withholding tax 818 8,573 Employee compensation and severance 8,414 10,900 Other 5,078 8,572 $ 70,778 $ 187,831

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Obligations, Firm Agreements and Leases As at December 31, 2015 , future minimum payments under non-cancelable agreements with remaining terms in excess of one year were as follows: Year ending December 31 Total 2016 2017 2018 2019 2020 Thereafter (Thousands of U.S. Dollars) Oil transportation services $ 18,441 $ 3,650 $ 3,640 $ 3,640 $ 3,640 $ 3,640 $ 231 Drilling, completions and seismic 7,572 2,918 2,667 1,987 — — — Operating leases 7,140 3,103 2,647 1,389 1 — — Software and telecommunication 479 351 128 — — — — $ 33,632 $ 10,022 $ 9,082 $ 7,016 $ 3,641 $ 3,640 $ 231 Gran Tierra leases certain office space, compressors, vehicles, equipment and housing. Total rent expense for the year ended December 31, 2015 , was $4.0 million ( year ended December 31, 2014 – $3.2 million ; year ended December 31, 2013 - $3.1 million ). Indemnities Corporate indemnities have been provided by the Company to directors and officers for various items including, but not limited to, all costs to settle suits or actions due to their association with the Company and its subsidiaries and/or affiliates, subject to certain restrictions. The Company has purchased directors’ and officers’ liability insurance to mitigate the cost of any potential future suits or actions. The maximum amount of any potential future payment cannot be reasonably estimated. The Company may provide indemnifications in the normal course of business that are often standard contractual terms to counterparties in certain transactions such as purchase and sale agreements. The terms of these indemnifications will vary based upon the contract, the nature of which prevents the Company from making a reasonable estimate of the maximum potential amounts that may be required to be paid. The Company provided the purchaser of its Argentina business unit with certain indemnifications. The Company remains responsible for certain contingent liabilities related to such indemnifications, subject to defined limitations. The Company does not believe that these obligations are probable of having a material impact on its consolidated financial position, results of operations or cash flows. Letters of credit At December 31, 2015 , the Company had provided promissory notes totaling $76.5 million ( December 31, 2014 - $86.3 million ) as security for letters of credit relating to work commitment guarantees contained in exploration contracts and other capital or operating requirements. Contingencies Gran Tierra’s production from the Costayaco Exploitation Area is subject to an additional royalty (the "HPR royalty"), which applies when cumulative gross production from an Exploitation Area is greater than five MMbbl. The HPR royalty is calculated on the difference between a trigger price defined in the Chaza Block exploration and production contract (the "Chaza Contract") and the sales price. The Agencia Nacional de Hidrocarburos (National Hydrocarbons Agency) (“ANH”) has interpreted the Chaza Contract as requiring that the HPR royalty must be paid with respect to all production from the Moqueta Exploitation Area and initiated a noncompliance procedure under the Chaza Contract, which was contested by Gran Tierra because the Moqueta Exploitation Area and the Costayaco Exploitation Area are separate Exploitation Areas. ANH did not proceed with that noncompliance procedure. Gran Tierra also believes that the evidence shows that the Costayaco and Moqueta Fields are two clearly separate and independent hydrocarbon accumulations. Therefore, it is Gran Tierra’s view that, pursuant to the terms of the Chaza Contract, the HPR royalty was only to be paid with respect to production from the Moqueta Exploitation Area when the accumulated oil production from that Exploitation Area exceeded five MMbbl. Discussions with the ANH have not resolved this issue and Gran Tierra has initiated the dispute resolution process under the Chaza Contract by filing on January 14, 2013, an arbitration claim before the Center for Arbitration and Conciliation of the Chamber of Commerce of Bogotá, Colombia, seeking a decision that the HPR royalty is not payable until production from the Moqueta Exploitation Area exceeds five MMbbl. Gran Tierra supplemented its claim on May 30, 2013. The ANH filed a response to the claim seeking a declaration that its interpretation is correct and a counterclaim seeking, amongst other remedies, declarations that Gran Tierra breached the Chaza Contract by not paying the disputed HPR royalty, that the amount of the alleged HPR royalty is payable, and that the Chaza Contract be terminated. Gran Tierra filed a response to the ANH's counterclaim and filed its comments on the ANH's responses to Gran Tierra's claim. The ANH filed an amended counterclaim and Gran Tierra filed a response to the ANH's amended counterclaim. On April 30, 2015, total cumulative production from the Moqueta Exploitation Area reached 5.0 MMbbl and Gran Tierra commenced paying the HPR royalty payable on production over that threshold. The estimated compensation which would be payable on cumulative production if the ANH's claims are accepted in the arbitration is $66.3 million plus related interest of $26.5 million . Gran Tierra also disagrees with the interest rate that the ANH has used in calculating the interest cost. Gran Tierra asserts that since the HPR royalty is denominated in the U.S. dollar, the contract requires the interest rate to be three-month LIBOR plus 4% , whereas the ANH has applied the highest legally authorized interest rate on Colombian peso liabilities, which during the period of production to date has averaged approximately 29% per annum. At December 31, 2015 , based on an interest rate of three-month LIBOR plus 4% related interest would be $6.4 million . At this time no amount has been accrued in the consolidated financial statements nor deducted from the Company's reserves for the disputed HPR royalty as Gran Tierra does not consider it probable that a loss will be incurred. Additionally, the ANH and Gran Tierra are engaged in discussions regarding the interpretation of whether certain transportation and related costs are eligible to be deducted in the calculation of the HPR royalty. Discussions with the ANH are ongoing. Based on the Company's understanding of the ANH's position, the estimated compensation which would be payable if the ANH’s interpretation is correct could be up to $44.8 million as at December 31, 2015 . At this time no amount has been accrued in the consolidated financial statements as Gran Tierra does not consider it probable that a loss will be incurred. Other gains and losses in the three years ended December 31, 2015 , related to a contingent loss accrued in connection with a legal dispute. In 2013, the Company received an adverse legal judgment and the amount awarded in the legal judgment was denominated in bbl of oil. The Company filed an appeal against the judgment. Other gains in the year ended December 31, 2014, related to a reduction in the value of this contingent loss due to lower oil prices. During the three months ended December 31, 2015, the Company received an adverse legal judgment from the appeal court. The Company paid $1.9 million , the amount awarded by the appeal court, during the fourth quarter of 2015 and a gain of $0.5 million was recognized as a result of a reduction in the value of the previously recognized contingent loss. In addition to the above, Gran Tierra has several other lawsuits and claims pending. Although the outcome of these other lawsuits and disputes cannot be predicted with certainty, Gran Tierra believes the resolution of these matters would not have a material adverse effect on the Company’s consolidated financial position, results of operations or cash flows. Gran Tierra records costs as they are incurred or become probable and determinable.

Financial Instruments, Fair Val

Financial Instruments, Fair Value Measurement, Credit Risk and Foreign Exchange Risk	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk	Financial Instruments, Fair Value Measurement, Credit Risk and Foreign Exchange Risk Financial Instruments At December 31, 2015 , the Company’s financial instruments recognized in the balance sheet consist of cash and cash equivalents, restricted cash, accounts receivable, trading securities, accounts payable, accrued liabilities and contingent consideration included in other long-term liabilities. Fair Value Measurement The fair value of the trading securities and contingent consideration are being remeasured at the estimated fair value at each reporting period. The fair value of the trading securities which were received as consideration on the sale of the Company's Argentina business unit (Note 3) is estimated based on quoted market prices in an active market. The fair value of the contingent consideration, which relates to the acquisition of the remaining 30% working interest in certain properties in Brazil, is estimated based on the consideration expected to be transferred and discounted back to present value by applying an appropriate discount rate that reflected the risk factors associated with the payment streams. The discount rate used is determined in accordance with accepted valuation methods. The fair value of foreign currency derivatives was based on the estimated maturity value of foreign exchange non-deliverable forward contracts using applicable forward exchange rates. The most significant variable to the cash flow calculations is the estimation of forward foreign exchange rates. The resulting future cash inflows or outflows at maturity of the contracts are the net value of the contract. The fair value of the trading securities, foreign currency derivative liability and contingent consideration at December 31, 2015 , and December 31, 2014 were as follows: As at December 31, (Thousands of U.S. Dollars) 2015 2014 Trading securities $ 6,250 $ 7,586 Foreign currency derivative liability $ — $ 3,057 Contingent consideration liability 1,061 1,061 $ 1,061 $ 4,118 The following table presents losses or gains on financial instruments recognized in the accompanying consolidated statements of operations: (Thousands of U.S. Dollars) Year Ended December 31, 2015 2014 2013 Trading securities loss $ 1,335 $ 6,326 $ — Foreign currency derivatives loss (gain) 692 (1,604 ) — $ 2,027 $ 4,722 $ — These losses are presented as financial instruments loss in the consolidated statements of operations and cash flows. There were no sales of trading securities in the three years ended December 31, 2015 , and the trading securities loss represents an unrealized loss. The fair value of long-term restricted cash approximates its carrying value because interest rates are variable and reflective of market rates. The fair values of other financial instruments approximate their carrying amounts due to the short-term maturity of these instruments. GAAP establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. This hierarchy consists of three broad levels. Level 1 inputs consist of quoted prices (unadjusted) in active markets for identical assets and liabilities and have the highest priority. Level 2 and 3 inputs are based on significant other observable inputs and significant unobservable inputs, respectively, and have lower priorities. The Company uses appropriate valuation techniques based on the available inputs to measure the fair values of assets and liabilities. At December 31, 2015 and December 31, 2014 , the fair value of the trading securities acquired in connection with the disposal of the Argentina business unit was determined using Level 1 inputs. At December 31, 2014 , the fair value of the foreign currency derivatives was determined using Level 2 inputs. At December 31, 2015 , and December 31, 2014 , the fair value of the contingent consideration payable in connection with the Brazil acquisition was determined using Level 3 inputs. The disclosure in the paragraph above regarding the fair value of cash and restricted cash is based on Level 1 inputs. The Company’s non-recurring fair value measurements include asset retirement obligations. The fair value of an asset retirement obligation is measured by reference to the expected future cash outflows required to satisfy the retirement obligation discounted at the Company’s credit-adjusted risk-free interest rate. The significant level 3 inputs used to calculate such liabilities include estimates of costs to be incurred, the Company’s credit-adjusted risk-free interest rate, inflation rates and estimated dates of abandonment. Accretion expense is recognized over time as the discounted liabilities are accreted to their expected settlement value, while the asset retirement cost is amortized over the estimated productive life of the related assets. Foreign Exchange Risk Unrealized foreign exchange gains and losses primarily result from fluctuation of the U.S. dollar to the Colombian peso due to Gran Tierra’s current and deferred tax liabilities, which are monetary liabilities mainly denominated in the local currency of the Colombian operations. As a result, foreign exchange gains and losses must be calculated on conversion to the U.S. dollar functional currency. A strengthening in the Colombian peso against the U.S. dollar results in foreign exchange losses, estimated at $10,000 for each one peso decrease in the exchange rate of the Colombian peso to one U.S. dollar . From time to time, the Company purchases non-deliverable forward contracts for purposes of fixing exchange rates at which it will purchase or sell Colombian pesos to settle its income tax installment payments. At December 31, 2015 , the Company did not have any open foreign currency derivative positions. With the exception of these foreign currency derivatives, any foreign currency transactions are conducted on a spot basis with major financial institutions in the Company’s operating areas. For the year ended December 31, 2015 , 97% ( year ended December 31, 2014 - 95% , year ended December 31, 2013 - 96% ) of the Company's oil and natural gas sales were generated in Colombia. In Colombia, the Company receives 100% of its revenues in U.S. dollars and the majority of its capital expenditures are in U.S. dollars or are based on U.S. dollar prices. In Brazil, prices for oil are in U.S. dollars, but revenues are received in local currency translated according to current exchange rates. The majority of the Company's capital expenditures within Brazil are based on U.S. dollar prices, but are paid in local currency translated according to current exchange rates. In Peru, capital expenditures are based on U.S. dollar prices and may be paid in local currency or U.S. dollars. Credit Risk Credit risk arises from the potential that the Company may incur a loss if a counterparty to a financial instrument fails to meet its obligation in accordance with agreed terms. The Company’s financial instruments that are exposed to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash and accounts receivable. The carrying value of cash and cash equivalents, restricted cash and accounts receivable reflects management’s assessment of credit risk . At December 31, 2015 , cash and cash equivalents and restricted cash included balances in bank accounts, term deposits and certificates of deposit, placed with financial institutions with strong investment grade ratings or governments. Most of the Company’s accounts receivable relate to uncollateralized sales to customers in the oil and natural gas industry and are exposed to typical industry credit risks. The concentration of revenues in a single industry affects the Company’s overall exposure to credit risk because customers may be similarly affected by changes in economic and other conditions. The Company manages this credit risk by entering into sales contracts with only credit worthy entities and reviewing its exposure to individual entities on a regular basis. For the year ended December 31, 2015 , the Company had four customers which were significant to the Colombian segment, and one customer which was significant to the Brazil segment. To reduce the concentration of exposure to any individual counterparty, the Company utilizes a group of investment-grade rated counterparties, primarily financial institutions, for its derivative transactions. The Company monitors counterparty creditworthiness on an ongoing basis; however, it cannot predict sudden changes in counterparties’ creditworthiness. In addition, even if such changes are not sudden, the Company may be limited in its ability to mitigate an increase in counterparty credit risk. Should one of these counterparties not perform, the Company may not realize the benefit of some of its foreign currency derivative instruments.

Severance Expenses

Severance Expenses	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
Severance Expenses	Severance Expenses During the year ended December 31, 2015, the Company reduced the number of its employees and contractors. Severance expenses were recorded as incurred based on existing employee contracts, statutory requirements, completed negotiations and company policy. Severance expenses for the Company’s reportable segments and other activities for the year ended December 31, 2015 , were as follows: Year Ended December 31, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Severance expenses $ 1,837 $ 2,096 $ 374 $ 4,683 $ 8,990 The amounts in the table represent cumulative costs incurred to date and exclude the impact of the reversal of stock-based compensation expense for unvested options of terminated employees which was recorded in G&A expenses. Changes in the severance cost related liability were as follows: (Thousands of U.S. Dollars) Year Ended December 31, 2015 Balance, December 31, 2014 $ — Liability incurred 8,990 Settlements (7,526 ) Balance, December 31, 2015 $ 1,464

Credit Facility

Credit Facility	12 Months Ended
	Dec. 31, 2015
Line of Credit Facility [Abstract]
Credit Facility	Credit Facility At December 31, 2015 , the Company had a credit facility with a syndicate of lenders. Availability under the credit facility is determined by a proven reserves-based borrowing base, and remains subject to the satisfaction of conditions precedent set forth in the credit agreement. Loans under the credit agreement will mature on September 18, 2018. The initial borrowing base is $200 million and the borrowing base will be re-determined semi-annually based on reserve evaluation reports, subject to a maximum of $500 million . The borrowing base for the credit facility is supported by the present value of the petroleum reserves of two of the Company's subsidiaries with operating branches in Colombia. The credit agreement includes a letter of credit sub-limit of up to $100 million . Amounts drawn down under the facility bear interest, at the Company's option, at the USD LIBOR rate plus a margin ranging from 2.00% and 3.00% per annum, or an alternate base rate plus a margin ranging from 1.00% per annum to 2.00% per annum, in each case based on the borrowing base utilization percentage. Undrawn amounts under the credit facility bear interest at 0.75% per annum, based on the average daily amount of unused commitments. A letter of credit participation fee of 0.25% per annum will accrue on the average daily amount of letter of credit exposure. Under the terms of the credit facility, the Company is required to maintain and was in compliance with certain financial and operating covenants. No amounts have been drawn on this facility. This credit facility was entered into and became effective on September 18, 2015, and replaced the Company's previous credit facility which was canceled on this date. Under the terms of the credit facility, the Company cannot pay any dividends to its shareholders if it is in default under the facility and, if the Company is not in default, it is required to obtain bank approval for dividend payments to shareholders outside of the credit facility group.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2015
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Net changes in assets and liabilities from operating activities of continuing operations were as follows: Year Ended December 31, 2015 2014 2013 Accounts receivable and other long-term assets $ 44,365 $ (34,473 ) $ 58,955 Inventory (1,571 ) (2,891 ) 14,168 Prepaids 152 4 (2,458 ) Accounts payable and accrued and other long-term liabilities (34,493 ) 558 (8,754 ) Taxes receivable and payable (48,251 ) (61,064 ) 84,687 Net changes in assets and liabilities from operating activities of continuing operations $ (39,798 ) $ (97,866 ) $ 146,598 The following table provides additional supplemental cash flow disclosures: Year Ended December 31, 2015 2014 2013 Cash paid for income taxes $ 39,422 $ 101,179 $ 51,183 Non-cash investing activities: Net liabilities related to property, plant and equipment, end of year $ 33,923 $ 113,874 $ 75,580 Acquisition of marketable securities as proceeds from sale of Argentina business unit (Note 3) $ — $ 13,912 $ —

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent events	Subsequent events a) On January 13, 2016, (the “Petroamerica Acquisition Date”), the Company acquired all of the issued and outstanding common shares of Petroamerica Oil Corp. ("Petroamerica"), a Canadian corporation, pursuant to the terms and conditions of an arrangement agreement dated November 12, 2015, (the “Arrangement”). Petroamerica is a Calgary based oil and gas exploration, development and production company active in Colombia. The transaction contemplated by the Arrangement was effected through a court approved plan of arrangement in Canada. The Arrangement was approved at a special meeting of Petroamerica shareholders and by the Court of Queen's Bench of Alberta on January 11, 2016. Under the Arrangement, Petroamerica shareholders received, for each Petroamerica share held, either 0.40 of a Gran Tierra common share or $1.33 Canadian dollars in cash. As consideration for the acquisition of all the issued and outstanding Petroamerica shares, the Company issued of 13,656,719 shares of Gran Tierra Common Stock, par value $0.001 , and paid cash consideration of $70.6 million . The fair value of Gran Tierra’s Common Stock issued was determined to be $25.8 million based on the closing price of shares of Common Stock of Gran Tierra as at the Petroamerica Acquisition Date. Total net purchase price of Petroamerica was $70.4 million , after giving consideration to estimated net working capital of $26.0 million . Upon completion of the transaction on the Petroamerica Acquisition Date, Petroamerica became an indirect wholly-owned subsidiary of Gran Tierra. Upon the closing of the Arrangement, Petroamerica and Gran Tierra security holders owned approximately 4.6% and 95.4% of Gran Tierra respectively, immediately following the transaction. The total consideration for the transaction was $96.4 million . b) On January 25, 2016 , the Company acquired all of the issued and outstanding common shares of PetroGranada Colombia Limited ("PGC"), pursuant to the terms and conditions of an acquisition agreement dated January 14, 2016. The net purchase price of PGC was $19.0 million , after giving consideration to estimated net working capital of $18.7 million . Contingent consideration of $4.0 million will be payable if cumulative production from the Putumayo-7 Block plus gross proved plus probable reserves under the Putumayo Block meet or exceed 8 MMbbl. PGC is an oil and gas exploration, development and production company active in Colombia. Upon completion of the transaction, PGC became an indirect wholly-owned subsidiary of Gran Tierra. Due to the limitations on access to Petroamerica and PGC information prior to the closing dates of the acquisitions, and the limited time since the acquisitions closed, the initial accounting for the acquisitions is incomplete at this time. As a result, the Company is unable to disclose amounts recognized as of the acquisition dates for the major classes of assets acquired and liabilities assumed, including the information required for net working capital and goodwill, if any. This information will be included in the Company's first quarter 2016 Quarterly Report on Form 10-Q.

Significant Accounting Polici23

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Basis of consolidation	Basis of consolidation These consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated.
Discontinued operations	Discontinued operations On June 25, 2014, the Company completed the sale of its Argentina business unit and the discontinued operations criteria of Accounting Standards Codification ("ASC") 205-20, “ Discontinued Operations ”, were met. Therefore, the results of the Company’s Argentina business unit are reflected separately as loss from discontinued operations, net of income taxes, in the consolidated statement of operations for the two years ended December 31, 2014, on a line immediately after “Loss or income from continuing operations.” Additionally, cash flows of the Company’s Argentina business unit are reflected separately in the consolidated statement of cash flows for the two years ended December 31, 2014, as cash provided by or used in operating and investing activities of discontinued operations. See Note 3, “Discontinued Operations,” for additional disclosure. The Company did not recognize depletion, depreciation and accretion ("DD&A") expenses for the Argentina business unit subsequent to May 29, 2014, the date the assets were classified as held for sale.
Use of estimates	Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates made by management include: oil and natural gas reserves and related present value of future cash flows; depreciation, depletion, amortization and impairment (“DD&A”); impairment assessments of goodwill; timing of transfers from oil and gas properties not subject to depletion to the depletable base; asset retirement obligations; determining the value of the consideration transferred and the net identifiable assets acquired and liabilities assumed in connection with business combinations and determining goodwill; assessments of the likely outcome of legal and other contingencies; income taxes; stock-based compensation; and determining the fair value of foreign currency derivatives. Although management believes these estimates are reasonable, changes in facts and circumstances or discovery of new information may result in revised estimates and actual results may differ from these estimates.
Cash and cash equivalents	Cash and cash equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents.
Restricted cash	Restricted cash Restricted cash is included in other current assets and other long-term assets on the Company's balance sheet. Restricted cash comprises cash and cash equivalents pledged to secure letters of credit and to settle asset retirement obligations. Letters of credit currently secured by cash relate to work commitment guarantees contained in exploration contracts. Cash and claims to cash that are restricted as to withdrawal or use for other than current operations or are designated for expenditure in the acquisition or construction of long-term assets are excluded from the current asset classification.
Allowance for doubtful accounts	Allowance for doubtful accounts The Company estimates losses on receivables based on known uncollectible accounts, if any, and historical experience of losses incurred and accrues a reserve on a receivable when, based on the judgment of management, it is probable that a receivable will not be collected and the amount of the reserve may be reasonably estimated.
Marketable securities	Marketable securities The Company acquired investments in marketable securities in connection with the sale of its Argentina business unit in 2014. Marketable securities are classified as trading securities, in accordance with ASC 320, “ Investments – Debt and Equity Securities ”, and are recorded in the consolidated balance sheet at fair value. The Company classifies trading securities as current or non-current based on the intent of management, the nature of the trading securities and whether they are readily available for use in current operations. Gains or losses on trading securities are recorded in the statement of operations as financial instruments gains or losses.
Foreign currency derivatives	Foreign currency derivatives The Company has, from time to time, purchased Colombian peso non-deliverable forward contracts for purposes of fixing exchange rates at which it will purchase or sell Colombian pesos to settle its income tax installment payments. The Company does not intend to issue or hold derivative financial instruments for speculative trading purposes. The Company records derivative instruments on the balance sheet as either an asset or liability measured at fair value. The accounting for changes in the fair value of a derivative instrument depends on the intended use of the derivative and the resulting designation, which is established at the inception of a derivative. Generally because of the short-term nature of the contracts and their limited use, the Company does not apply hedge accounting and changes in the fair value of those contracts are reflected in net income or loss as financial instrument gains or losses in the consolidated statement of operations. Cash settlements of the Company's derivative arrangements are classified as operating cash flows. The fair value of foreign currency derivatives is based on the estimated maturity value of the foreign exchange non-deliverable forward contracts, using applicable forward exchange rates. The most significant variable to the cash flow calculations is the estimation of forward foreign exchange rates. The resulting net future cash inflows or outflows at maturity of the contracts are the net value of the contract.
Inventory	Inventory Inventory consists of oil in tanks and third party pipelines and supplies and is valued at the lower of cost or market value. The cost of inventory is determined using the weighted average method. Oil inventories include expenditures incurred to produce, upgrade and transport the product to the storage facilities and include operating, depletion and depreciation expenses and cash royalties.
Income taxes	Income taxes Income taxes are recognized using the liability method, whereby deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax base, and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. Valuation allowances are provided if, after considering available evidence, it is not more likely than not that some or all of the deferred tax assets will be realized. The tax benefit from an uncertain tax position is recognized when it is more likely than not, based on the technical merits of the position, that the position will be sustained on examination by the taxing authorities. Additionally, the amount of the tax benefit recognized is the largest amount of benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. In evaluating whether a tax position has met the more-likely-than-not recognition threshold, the Company presumes that the position will be examined by the appropriate taxing authority that has full knowledge of all relevant information. The Company recognizes potential penalties and interest related to unrecognized tax benefits as a component of income tax expense.
Oil and gas properties	Oil and gas properties The Company uses the full cost method of accounting for its investment in oil and natural gas properties as defined by the Securities and Exchange Commission (“SEC”). Under this method, the Company capitalizes all acquisition, exploration and development costs incurred for the purpose of finding oil and natural gas reserves, including salaries, benefits and other internal costs directly attributable to these activities. Costs associated with production and general corporate activities; however, are expensed as incurred. Interest costs related to unproved properties and properties under development are also capitalized to oil and natural gas properties. Separate cost centers are maintained for each country in which the Company incurs costs. The Company computes depletion of oil and natural gas properties on a quarterly basis using the unit-of-production method based upon production and estimates of proved reserve quantities. Future development costs related to properties with proved reserves are also included in the amortization base for computation of depletion. The costs of unproved properties are excluded from the amortization base until the properties are evaluated. The cost of exploratory dry wells is transferred to proved properties, and thus is subject to amortization, immediately upon determination that a well is dry in those countries where proved reserves exist. The Company performs a ceiling test calculation each quarter in accordance with SEC Regulation S-X Rule 4-10. In performing its quarterly ceiling test, the Company limits, on a country-by-country basis, the capitalized costs of proved oil and natural gas properties, net of accumulated depletion and deferred income taxes, to the estimated future net cash flows from proved oil and natural gas reserves discounted at 10% , net of related tax effects, plus the lower of cost or fair value of unproved properties included in the costs being amortized. If such capitalized costs exceed the ceiling, the Company will record a write-down to the extent of such excess as a non-cash charge to net income or loss. Any such write-down will reduce earnings in the period of occurrence and results in a lower DD&A rate in future periods. A write-down may not be reversed in future periods even though higher oil and natural gas prices may subsequently increase the ceiling. The Company calculates future net cash flows by applying the unweighted average of prices in effect on the first day of the month for the preceding 12-month period, adjusted for location and quality differentials. Such prices are utilized except where different prices are fixed and determinable from applicable contracts for the remaining term of those contracts. Unproved properties are not depleted pending the determination of the existence of proved reserves. Costs are transferred into the depletable base on an ongoing basis as the properties are evaluated and proved reserves are established or impairment is determined. Unproved properties are evaluated quarterly to ascertain whether impairment has occurred. This evaluation considers, among other factors, seismic data, requirements to relinquish acreage, drilling results and activity, remaining time in the commitment period, remaining capital plans, and political, economic, and market conditions. During any period in which factors indicate an impairment, the cumulative costs incurred to date for such property are transferred to the full cost pool and are then subject to depletion. For countries where a reserve base has not yet been established, the impairment is charged to earnings. In exploration areas, related seismic costs are capitalized in unproved property and evaluated as part of the total capitalized costs associated with a property. Seismic costs related to development projects are recorded in proved properties and therefore subject to depletion as incurred. Gains and losses on the sale or other disposition of oil and natural gas properties are not recognized, unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves of oil and natural gas attributable to a country.
Asset retirement obligation	Asset retirement obligation The Company records an estimated liability for future costs associated with the abandonment of its oil and gas properties including the costs of reclamation of drilling sites. The Company records the fair value of a liability for a legal obligation to retire an asset in the period in which the liability is incurred with an offsetting increase to the related oil and gas properties. The fair value of an asset retirement obligation is measured by reference to the expected future cash outflows required to satisfy the retirement obligation discounted at the Company’s credit-adjusted risk-free interest rate. Accretion expense is recognized over time as the discounted liabilities are accreted to their expected settlement value, while the asset retirement cost is amortized over the estimated productive life of the related assets. The accretion of the asset retirement obligation and amortization of the asset retirement cost are included in DD&A. If estimated future costs of an asset retirement obligation change, an adjustment is recorded to both the asset retirement obligation and oil and gas properties. Revisions to the estimated asset retirement obligation can result from changes in retirement cost estimates, revisions to estimated inflation rates and changes in the estimated timing of abandonment.
Other capital assets	Other capital assets Other capital assets, including additions and replacements, are recorded at cost upon acquisition and include furniture, fixtures and leasehold improvement, computer equipment and automobiles. Depreciation is provided using the declining-balance method at a 30% annual rate for furniture and fixtures, computer equipment and automobiles. Leasehold improvements are depreciated on a straight-line basis over the shorter of the estimated useful life and the term of the related lease. The cost of repairs and maintenance is charged to expense as incurred.
Goodwill	Goodwill Goodwill represents the excess of the aggregate of the consideration transferred over the net identifiable assets acquired and liabilities assumed. The Company assesses qualitative factors annually, or more frequently if necessary, to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount and whether it is necessary to perform the two-step goodwill impairment test. The impairment test requires allocating goodwill and certain other assets and liabilities to assigned reporting units. The fair value of each reporting unit is estimated and compared with the net book value of the reporting unit. If the estimated fair value of the reporting unit is less than the net book value, including goodwill, then the goodwill is written down to the implied fair value of the goodwill through a charge to expense. Because quoted market prices are not available for the Company’s reporting units, the fair values of the reporting units are estimated based upon estimated future cash flows of the reporting unit.
Revenue recognition	Revenue recognition Revenue from the production of oil and natural gas is recognized when the customer has taken title and has assumed the risks and rewards of ownership, prices are fixed or determinable, the sale is evidenced by a contract and collection of the revenue is reasonably assured. In Colombia, the sales point for the Company's sales varies depending on the delivery point but includes the Port of Tumaco on the Pacific coast of Colombia, the purchaser's facilities and when oil is loaded into a truck at Gran Tierra's loading facility or an export tanker. In Brazil, the sales point is either the Petróleo Brasileiro S.A station or the purchaser's facility. Revenue represents the Company’s share and is recorded net of royalty payments to governments and other mineral interest owners.
Stock-based compensation	Stock-based compensation The Company grants time-vested restricted stock units ("RSUs") to officers, employees and consultants. RSUs entitle the holder to receive, at the option of the Company, either the underlying number of shares of the Company's Common Stock upon vesting of such shares or a cash payment equal to the value of the underlying shares. The Company's practice is to settle RSUs in cash and, therefore, RSUs are accounted for as liability instruments. Compensation expense for RSUs granted is based on the estimated fair value, which is determined using the closing share price, at each reporting date, and the expense, net of estimated forfeitures, is recognized over the requisite service period using the accelerated method, with a corresponding change to liabilities. An adjustment is made to compensation expense for any difference between the estimated forfeitures and the actual forfeitures. Additionally, the Company grants options to purchase shares of Common Stock to certain directors, officers, employees and consultants. The Company follows the fair-value based method of accounting for stock options granted. Compensation expense for options granted is based on the estimated fair value, using the Black-Scholes option pricing model, at the time of grant and the expense, net of estimated forfeitures, is recognized over the requisite service period using the accelerated method. An adjustment is made to compensation expense for any difference between the estimated forfeitures and the actual forfeitures . The Company uses historical data to estimate expected term used in the Black-Scholes option pricing model, option exercises and employee departure behavior. Expected volatilities used in the fair value estimate are based on historical volatility of the Company’s shares. The risk-free rate for periods within the expected term of the stock options is based on the U.S. Treasury yield curve in effect at the time of grant. Stock-based compensation expense relating to RSUs and stock options is capitalized as part of oil and natural gas properties or expensed as part of operating expenses or general and administrative (“G&A”) expenses, as appropriate.
Foreign currency translations	Foreign currency translation The functional currency of the Company, including its subsidiaries, is the United States dollar. Monetary items are translated into the reporting currency at the exchange rate in effect at the balance sheet date and non-monetary items are translated at historical exchange rates. Revenue and expense items are translated in a manner that produces substantially the same reporting currency amounts that would have resulted had the underlying transactions been translated on the dates they occurred. Depreciation or amortization of assets is translated at the historical exchange rates similar to the assets to which they relate. Gains and losses resulting from foreign currency transactions, which are transactions denominated in a currency other than the entity’s functional currency, are recognized in net income or loss.
Net income or loss per share	Net income or loss per share Basic net income or loss per share is calculated by dividing net income or loss attributable to common shareholders by the weighted average number of shares of Common Stock and exchangeable shares issued and outstanding during each period. Diluted net income or loss per share is calculated by adjusting the weighted average number of shares of Common Stock and exchangeable shares outstanding for the dilutive effect, if any, of share equivalents. The Company uses the treasury stock method to determine the dilutive effect. This method assumes that all Common Stock equivalents have been exercised at the beginning of the period (or at the time of issuance, if later), and that the funds obtained thereby were used to purchase shares of Common Stock of the Company at the volume weighted average trading price of shares of Common Stock during the period.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Revenue from Contracts with Customers In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers ". The ASU creates a single source of revenue guidance for all companies in all industries and requires revenue recognition to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 sets forth a new revenue recognition model that requires identifying the contract, identifying the performance obligations, determining the transaction price, allocating the transaction price to performance obligations and recognizing the revenue upon satisfaction of performance obligations. The amendments in the ASU can be applied either retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the update recognized at the date of the initial application along with additional disclosures. In August 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers - Deferral of the Effective Date". The ASU defers the effective date of the new revenue recognition model by one year. As a result, the guidance will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. The Company is currently assessing the impact the new standard will have on its consolidated financial position, results of operations, cash flows, and disclosure. Simplifying the Measurement of Inventory In July 2015, the FASB issued ASU 2015-11, “Simplifying the Measurement of Inventory". The ASU provides guidance for the subsequent measurement of inventory and requires that inventory that is measured using average cost be measured at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The ASU will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The implementation of this update is not expected to materially impact the Company’s consolidated financial position, results of operations or cash flows or disclosure. Simplifying the Accounting for Measurement-Period Adjustments In September 2015, the FASB issued ASU 2015-16, "Simplifying the Accounting for Measurement-Period Adjustments". ASU 2015-16 requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. ASU 2015-16 is effective for fiscal years and interim reporting periods within those fiscal years, beginning after December 15, 2015. Prospective adoption is required. This ASU is not expected to have a material impact on the Company's consolidated financial position, results of operations or cash flows or disclosure. Balance Sheet Classification of Deferred Taxes In November 2015, the FASB issued ASU 2015-17, "Balance Sheet Classification of Deferred Taxes". ASU 2015-17 requires that deferred tax liabilities and assets be classified as long-term in a classified balance sheet . ASU 2015-17 is effective for annual reporting periods and interim reporting periods within those annual reporting periods, beginning after December 15, 2016. Early application is permitted. The amendments in this ASU may be applied either prospectively to all deferred tax liabilities and assets or retrospectively to all periods presented. The Company implemented this update retrospectively in its consolidated financial statements for the year ended December 31, 2015, so that the balance sheet is presented on a comparable basis. Deferred tax liabilities and assets of $1.0 million and $1.6 million , respectively, have been reclassified from current to long-term in the Company's December 31, 2014 balance sheet. The implementation of this update did not impact the Company’s consolidated results of operations or cash flows. Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, "Recognition and Measurement of Financial Assets and Financial Liabilities". ASU 2016-01 addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 is effective for annual reporting periods and interim reporting periods within those annual reporting periods, beginning after December 15, 2017. This ASU is not expected to have a material impact on the Company's consolidated financial position, results of operations or cash flows or disclosure.

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Revenue and Other Income and Loss from Discontinued Operations	Revenue and other income and loss from discontinued operations, net of income taxes, for the two years ended December 31, 2014, were as follows: Year Ended December 31, (Thousands of U.S. Dollars) 2014 2013 Revenue and other income $ 31,985 $ 74,514 Loss income from operations of discontinued operations before income taxes $ (6,252 ) $ (47,448 ) Income tax expense (1,458 ) (7,287 ) Loss from operations of discontinued operations (7,710 ) (54,735 ) Loss on sale before income taxes (18,235 ) — Income tax expense (1,045 ) — Loss on sale (19,280 ) — Loss from discontinued operations, net of income taxes $ (26,990 ) $ (54,735 ) Results from discontinued operations before income taxes for the year ended December 31, 2014, were calculated to the date of sale of June 25, 2014.

Segment and Geographic Report25

Segment and Geographic Reporting (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Reportable Geographic Segments	The following tables present information on the Company’s reportable segments and other activities: Year Ended December 31, 2015 (Thousands of U.S. Dollars, except per unit of sales amounts) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 269,035 $ — $ 6,976 $ — $ 276,011 Interest income 294 2 218 855 1,369 DD&A expenses 167,701 789 6,183 1,713 176,386 DD&A - per unit of sales 25.90 — 32.66 — 26.47 Asset impairment 235,069 41,916 46,933 — 323,918 General and administrative 9,805 3,800 2,708 16,040 32,353 Loss from continuing operations before income taxes (238,463 ) (51,675 ) (54,968 ) (22,982 ) (368,088 ) Segment capital expenditures 87,723 50,419 19,989 1,095 159,226 Year Ended December 31, 2014 (Thousands of U.S. Dollars, except per unit of sales amounts) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 532,196 $ — $ 27,202 $ — $ 559,398 Interest income 569 1 1,604 682 2,856 DD&A expenses 174,063 690 9,932 1,192 185,877 DD&A - per unit of sales 27.07 — 30.09 — 27.49 Asset impairment — 265,126 — — 265,126 General and administrative 19,431 6,448 3,698 21,672 51,249 Income (loss) from continuing operations before income taxes 279,924 (274,207 ) 5,921 (28,772 ) (17,134 ) Segment capital expenditures 214,928 174,158 24,278 2,868 416,232 Year Ended December 31, 2013 (Thousands of U.S. Dollars, except per unit of sales amounts) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 624,410 $ — $ 22,545 $ — $ 646,955 Interest income 623 27 909 615 2,174 DD&A expenses 184,697 362 14,761 1,031 200,851 DD&A - per unit of sales 27.23 — 61.75 — 28.60 Asset impairment — — 2,000 — 2,000 General and administrative 16,996 5,524 2,231 16,364 41,115 Income (loss) from continuing operations before income taxes 336,179 (7,067 ) (2,650 ) (17,178 ) 309,284 Segment capital expenditures (1) 188,547 82,954 23,039 775 295,315 (1) In 2013, segment capital expenditures are net of proceeds of: $54.0 million relating to termination of a farm-in agreement in Brazil; and $1.5 million relating to the Company's sale of its 15% working interest in the Mecaya Block in Colombia (Note 6).
Long-lived Assets by Geographical Area	As at December 31, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Property, plant and equipment $ 574,351 $ 95,069 $ 115,552 $ 4,021 $ 788,993 Goodwill 102,581 — — — $ 102,581 All other assets 93,479 21,111 2,236 137,718 $ 254,544 Total Assets $ 770,411 $ 116,180 $ 117,788 $ 141,739 $ 1,146,118 As at December 31, 2014 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Property, plant and equipment $ 888,822 $ 87,028 $ 148,457 $ 4,637 $ 1,128,944 Goodwill 102,581 — — — $ 102,581 All other assets 157,549 40,613 14,724 269,639 $ 482,525 Total Assets $ 1,148,952 $ 127,641 $ 163,181 $ 274,276 $ 1,714,050

Accounts Receivable and Inven26

Accounts Receivable and Inventory (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Schedule of Accounts Receivable	As at December 31, (Thousands of U.S. Dollars) 2015 2014 Trade $ 26,924 $ 80,058 Other 2,293 3,169 $ 29,217 $ 83,227

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	As at December 31, (Thousands of U.S. Dollars) 2015 2014 Oil and natural gas properties Proved $ 1,998,330 $ 1,876,371 Unproved 310,771 316,856 2,309,101 2,193,227 Other 28,342 27,287 2,337,443 2,220,514 Accumulated depletion, depreciation and impairment (1,548,450 ) (1,091,570 ) $ 788,993 $ 1,128,944
Schedule of Asset Impairment	Asset impairment for the three years ended December 31, 2015 , was follows: (Thousands of U.S. Dollars) Year Ended December 31, 2015 2014 2013 Impairment of oil and gas properties $ 321,285 $ 265,126 $ 2,000 Impairment of inventory (Note 5) 2,633 — — $ 323,918 $ 265,126 $ 2,000
Summary of Oil and Natural Gas Properties	The following is a summary of Gran Tierra’s oil and natural gas properties not subject to depletion as at December 31, 2015 : Costs Incurred in (Thousands of U.S. Dollars) 2015 2014 2013 Prior to 2013 Total Acquisition costs - Colombia $ — $ — $ — $ 67,597 $ 67,597 Acquisition costs - Peru — — — 21,147 21,147 Acquisition costs - Brazil — — — 35,525 35,525 Exploration costs - Colombia 11,151 35,952 20,103 12,697 79,903 Exploration costs - Peru 8,515 31,750 7,301 25,469 73,035 Exploration costs - Brazil 10,639 8,911 14,779 (765 ) 33,564 Total oil and natural gas properties not subject to depletion $ 30,305 $ 76,613 $ 42,183 $ 161,670 $ 310,771

Share Capital (Tables)

Share Capital (Tables)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Schedule of common stock	Shares of Common Stock Exchangeable Shares of Gran Tierra Exchangeco Inc. Exchangeable Shares of Gran Tierra Goldstrike Inc. Balance, December 31, 2014 276,072,351 5,595,118 4,524,627 Options exercised 390,000 — — Shares repurchased and canceled (4,567,136 ) — — Exchange of exchangeable shares 1,547,595 (661,857 ) (885,738 ) Shares canceled (11 ) (84 ) — Balance, December 31, 2015 273,442,799 4,933,177 3,638,889
Black Scholes option pricing model assumptions	The fair value of each stock option award is estimated on the date of grant using the Black-Scholes option pricing model based on assumptions noted in the following table: Year Ended December 31, 2015 2014 2013 Dividend yield (per share) Nil Nil Nil Volatility 46% to 50% 39% to 42% 42% to 54% Weighted average volatility 48 % 41 % 53 % Risk-free interest rate 1.20% to 1.68% 0.78% to 1.45% 0.3% to 0.7% Expected term 4-5 years 4-5 years 4-5 years
Stock options outstanding	The following table provides information about RSU and stock option activity for the year ended December 31, 2015 : RSUs Options Number of Outstanding Share Units Number of Outstanding Options Weighted Average Exercise Price $/Option Balance, December 31, 2014 1,236,963 13,790,220 $ 5.93 Granted 1,041,450 5,346,260 3.08 Exercised (531,012 ) (390,000 ) 1.85 Forfeited (731,944 ) (1,394,445 ) (5.63 ) Expired — (4,500,478 ) (6.78 ) Balance, December 31, 2015 1,015,457 12,851,557 $ 4.60 Exercisable, at December 31, 2015 7,784,678 $ 5.17 Vested, or expected to vest, at December 31, 2015, through the life of the options 12,494,309 $ 4.63
Amounts recognized for stock-based compensation	The amounts recognized for stock-based compensation were as follows: (Thousands of U.S. Dollars) Year Ended December 31, 2015 2014 2013 Compensation costs for stock options $ 2,263 $ 6,976 $ 8,418 Compensation costs for RSUs 629 2,559 2,936 2,892 9,535 11,354 Less: Stock-based compensation costs capitalized (159 ) (1,815 ) (2,436 ) Stock-based compensation costs expensed $ 2,733 $ 7,720 $ 8,918
Weighted average shares outstanding	Year Ended December 31, 2015 2014 2013 Weighted average number of common and exchangeable shares outstanding 285,333,869 284,715,785 282,808,497 Shares issuable pursuant to stock options — — 12,041,260 Shares assumed to be purchased from proceeds of stock options — — (8,721,860 ) Weighted average number of diluted common and exchangeable shares outstanding 285,333,869 284,715,785 286,127,897

Asset Retirement Obligation (Ta

Asset Retirement Obligation (Tables)	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation [Abstract]
Changes in Asset Retirement Obligations	Changes in the carrying amounts of the asset retirement obligation associated with the Company’s oil and natural gas properties were as follows: Year Ended December 31, (Thousands of U.S. Dollars) 2015 2014 Balance, beginning of year $ 35,812 $ 21,973 Settlements (6,317 ) (1,137 ) Liability incurred 1,556 11,956 Liabilities associated with the Argentina business unit sold — (10,170 ) Accretion 1,313 1,406 Revisions in estimated liability 860 11,784 Balance, end of year $ 33,224 $ 35,812 Asset retirement obligation - current $ 2,146 $ 8,026 Asset retirement obligation - long-term 31,078 27,786 Balance, end of year $ 33,224 $ 35,812

Taxes (Tables)

Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Tax Expense Reported Reconciliation To Computed Statutory Rate	The income tax expense reported differs from the amount computed by applying the U.S. statutory rate to income or loss from continuing operations before income taxes for the following reasons: Year Ended December 31, (Thousands of U.S. Dollars) 2015 2014 2013 (Loss) income from continuing operations before income taxes United States $ (14,061 ) $ (19,744 ) $ (13,566 ) Foreign (354,027 ) 2,610 322,850 (368,088 ) (17,134 ) 309,284 35 % 35 % 35 % Income tax (recovery) expense from continuing operations expected (128,831 ) (5,997 ) 108,249 Foreign currency translation adjustments (187 ) (6,520 ) (7,185 ) Impact of foreign taxes (1) (13,087 ) 27,910 (3,596 ) Other local taxes 2,354 4,433 3,673 Stock-based compensation 919 2,232 2,724 Increase in valuation allowance 37,691 94,922 21,423 Non-deductible third party royalty in Colombia 3,416 9,116 11,073 Other permanent differences (2) (2,334 ) 1,119 (8,100 ) Total income tax (recovery) expense from continuing operations $ (100,059 ) $ 127,215 $ 128,261 Current income tax expense from continuing operations United States $ 1,070 $ 1,260 $ 1,250 Foreign 14,313 91,605 155,876 15,383 92,865 157,126 Deferred income tax (recovery) expense from continuing operations Foreign (3) (115,442 ) 34,350 (28,865 ) Total income tax (recovery) expense from continuing operations $ (100,059 ) $ 127,215 $ 128,261 (1) Impact of foreign taxes in the rate reconciliation are tax effected at the 35% statutory rate and for the years ended December 31, 2015 and 2014, included $11.8 million and $28.1 million , respectively, in Colombia. (2) Other permanent differences in the rate reconciliation are tax effected at the 35% statutory rate. For the year ended December 31, 2013, these differences included $7.4 million of tax basis and loss adjustments, $5.0 million of which were offset by changes in the valuation allowance. (3) The deferred tax recovery for the year ended December 31, 2015, included $91.7 million associated with the ceiling test impairment loss in Colombia.
Deferred Tax Assets and Liabilities	As at December 31, (Thousands of U.S. Dollars) 2015 2014 Deferred Tax Assets Tax benefit of operating loss carryforwards $ 56,015 $ 51,248 Tax basis in excess of book basis 139,012 108,120 Foreign tax credits and other accruals 22,674 20,369 Tax benefit of capital loss carryforwards 30,799 29,984 Deferred tax assets before valuation allowance 248,500 209,721 Valuation allowance (245,259 ) (207,568 ) 3,241 2,153 Deferred Tax Liabilities 34,592 176,364 Net Deferred Tax Liabilities $ (31,351 ) $ (174,211 )
Changes in Unrecognized Tax Benefit	Changes in the Company's unrecognized tax benefit relating to loss or income from continuing operations are as follows: Year Ended December 31, 2015 2014 2013 (Thousands of U.S. Dollars) Unrecognized tax benefit relating to loss or income from continuing operations, beginning of year $ 3,300 $ 2,900 $ 5,900 Increases for positions relating to prior year — 500 — Decreases for positions relating to prior year (800 ) (100 ) (3,000 ) Decreases due to lapse of statute of limitations (300 ) — — Unrecognized tax benefit relating to loss or income from continuing operations, end of year $ 2,200 $ 3,300 $ 2,900

Accounts Payable and Accrued 31

Accounts Payable and Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	As at December 31, (Thousands of U.S. Dollars) 2015 2014 Trade $ 54,402 $ 148,998 Royalties 2,066 10,788 VAT and withholding tax 818 8,573 Employee compensation and severance 8,414 10,900 Other 5,078 8,572 $ 70,778 $ 187,831

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Contractual Obligations Future Lease Payments	As at December 31, 2015 , future minimum payments under non-cancelable agreements with remaining terms in excess of one year were as follows: Year ending December 31 Total 2016 2017 2018 2019 2020 Thereafter (Thousands of U.S. Dollars) Oil transportation services $ 18,441 $ 3,650 $ 3,640 $ 3,640 $ 3,640 $ 3,640 $ 231 Drilling, completions and seismic 7,572 2,918 2,667 1,987 — — — Operating leases 7,140 3,103 2,647 1,389 1 — — Software and telecommunication 479 351 128 — — — — $ 33,632 $ 10,022 $ 9,082 $ 7,016 $ 3,641 $ 3,640 $ 231

Financial Instruments, Fair V33

Financial Instruments, Fair Value Measurement, Credit Risk and Foreign Exchange Risk (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Trading Securities, Foreign Currency Derivative Liability and Contingent Consideration	The fair value of the trading securities, foreign currency derivative liability and contingent consideration at December 31, 2015 , and December 31, 2014 were as follows: As at December 31, (Thousands of U.S. Dollars) 2015 2014 Trading securities $ 6,250 $ 7,586 Foreign currency derivative liability $ — $ 3,057 Contingent consideration liability 1,061 1,061 $ 1,061 $ 4,118
Losses or Gains on Financial Instruments	The following table presents losses or gains on financial instruments recognized in the accompanying consolidated statements of operations: (Thousands of U.S. Dollars) Year Ended December 31, 2015 2014 2013 Trading securities loss $ 1,335 $ 6,326 $ — Foreign currency derivatives loss (gain) 692 (1,604 ) — $ 2,027 $ 4,722 $ —

Severance Expenses (Tables)

Severance Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
Expenses by Segment	Severance expenses for the Company’s reportable segments and other activities for the year ended December 31, 2015 , were as follows: Year Ended December 31, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Severance expenses $ 1,837 $ 2,096 $ 374 $ 4,683 $ 8,990
Change in Severance Expense Liability	Changes in the severance cost related liability were as follows: (Thousands of U.S. Dollars) Year Ended December 31, 2015 Balance, December 31, 2014 $ — Liability incurred 8,990 Settlements (7,526 ) Balance, December 31, 2015 $ 1,464

Supplemental Cash Flow Inform35

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2015
Supplemental Cash Flow Elements [Abstract]
Net Changes in Assets and Liabilities from Operating Activities	Net changes in assets and liabilities from operating activities of continuing operations were as follows: Year Ended December 31, 2015 2014 2013 Accounts receivable and other long-term assets $ 44,365 $ (34,473 ) $ 58,955 Inventory (1,571 ) (2,891 ) 14,168 Prepaids 152 4 (2,458 ) Accounts payable and accrued and other long-term liabilities (34,493 ) 558 (8,754 ) Taxes receivable and payable (48,251 ) (61,064 ) 84,687 Net changes in assets and liabilities from operating activities of continuing operations $ (39,798 ) $ (97,866 ) $ 146,598
Schedule of Cash Flow, Supplemental Disclosures	The following table provides additional supplemental cash flow disclosures: Year Ended December 31, 2015 2014 2013 Cash paid for income taxes $ 39,422 $ 101,179 $ 51,183 Non-cash investing activities: Net liabilities related to property, plant and equipment, end of year $ 33,923 $ 113,874 $ 75,580 Acquisition of marketable securities as proceeds from sale of Argentina business unit (Note 3) $ — $ 13,912 $ —

Significant Accounting Polici36

Significant Accounting Policies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2008	Dec. 31, 2006
Business Acquisition [Line Items]
Allowance for doubtful receivables	$ 0	$ 0
Depreciation rate for other capital assets	30.00%
Goodwill	$ 102,581,000	102,581,000
Goodwill impairment	$ 0
New Accounting Pronouncement, Early Adoption, Effect [Member]
Business Acquisition [Line Items]
Deferred tax liabilities, current		1,000,000
Deferred tax assets, current		$ 1,600,000
Solana [Member]
Business Acquisition [Line Items]
Goodwill			$ 87,600,000
Argosy [Member]
Business Acquisition [Line Items]
Goodwill				$ 15,000,000

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) - USD ($) $ in Thousands	Jun. 25, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Value of shares received		$ 0	$ 13,912	$ 0
Impairment loss		$ 321,285	$ 265,126	2,000
Argentina Business Unit [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate consideration	$ 69,300
Cash received	55,400
Argentina Business Unit [Member] | GTE ULC and PCESA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Value of shares received	$ 13,900
Argentina [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment loss				$ 30,800

Discontinued Operations - Reven

Discontinued Operations - Revenue and Other Income and Loss from Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]
Revenue and other income		$ 31,985	$ 74,514
Loss income from operations of discontinued operations before income taxes		(6,252)	(47,448)
Income tax expense		(1,458)	(7,287)
Loss from operations of discontinued operations		(7,710)	(54,735)
Loss on sale before income taxes		(18,235)	0
Income tax expense		(1,045)	0
Loss on sale		(19,280)	0
Loss from discontinued operations, net of income taxes	$ 0	$ (26,990)	$ (54,735)

Segment and Geographic Report39

Segment and Geographic Reporting (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / Unit	Dec. 31, 2014USD ($)$ / Unit	Dec. 31, 2013USD ($)$ / Unit
Disclosure on Geographic Areas, Description of Revenue from External Customers
Oil and natural gas sales	$ 276,011	$ 559,398	$ 646,955
Interest income	1,369	2,856	2,174
DD&A expenses	176,386	185,877	200,851
Asset impairment	323,918	265,126	2,000
General and administrative	32,353	51,249	41,115
Loss from continuing operations before income taxes	(368,088)	(17,134)	309,284
Proceeds from oil and gas properties	0	0	55,524
Brazil [Member]
Disclosure on Geographic Areas, Description of Revenue from External Customers
Asset impairment	46,900		2,000
Proceeds from termination of farm-in agreement			54,000
Colombia [Member] | Mecaya Block [Member]
Disclosure on Geographic Areas, Description of Revenue from External Customers
Proceeds from oil and gas properties			$ 1,500
Working interest sold, percentage			15.00%
Continuing Operations [Member]
Disclosure on Geographic Areas, Description of Revenue from External Customers
Oil and natural gas sales	276,011	559,398	$ 646,955
Interest income	1,369	2,856	2,174
DD&A expenses	$ 176,386	$ 185,877	$ 200,851
DD&A - per unit of sales | $ / Unit	26.47	27.49	28.60
Asset impairment	$ 323,918	$ 265,126	$ 2,000
General and administrative	32,353	51,249	41,115
Loss from continuing operations before income taxes	(368,088)	(17,134)	309,284
Segment capital expenditures	159,226	416,232	295,315
Operating Segments [Member] | Continuing Operations [Member] | Colombia [Member]
Disclosure on Geographic Areas, Description of Revenue from External Customers
Oil and natural gas sales	269,035	532,196	624,410
Interest income	294	569	623
DD&A expenses	$ 167,701	$ 174,063	$ 184,697
DD&A - per unit of sales | $ / Unit	25.90	27.07	27.23
Asset impairment	$ 235,069	$ 0	$ 0
General and administrative	9,805	19,431	16,996
Loss from continuing operations before income taxes	(238,463)	279,924	336,179
Segment capital expenditures	87,723	214,928	188,547
Operating Segments [Member] | Continuing Operations [Member] | Peru [Member]
Disclosure on Geographic Areas, Description of Revenue from External Customers
Oil and natural gas sales	0	0	0
Interest income	2	1	27
DD&A expenses	$ 789	$ 690	$ 362
DD&A - per unit of sales | $ / Unit	0	0	0
Asset impairment	$ 41,916	$ 265,126	$ 0
General and administrative	3,800	6,448	5,524
Loss from continuing operations before income taxes	(51,675)	(274,207)	(7,067)
Segment capital expenditures	50,419	174,158	82,954
Operating Segments [Member] | Continuing Operations [Member] | Brazil [Member]
Disclosure on Geographic Areas, Description of Revenue from External Customers
Oil and natural gas sales	6,976	27,202	22,545
Interest income	218	1,604	909
DD&A expenses	$ 6,183	$ 9,932	$ 14,761
DD&A - per unit of sales | $ / Unit	32.66	30.09	61.75
Asset impairment	$ 46,933	$ 0	$ 2,000
General and administrative	2,708	3,698	2,231
Loss from continuing operations before income taxes	(54,968)	5,921	(2,650)
Segment capital expenditures	19,989	24,278	23,039
All Other [Member] | Continuing Operations [Member] | All Other [Member]
Disclosure on Geographic Areas, Description of Revenue from External Customers
Oil and natural gas sales	0	0	0
Interest income	855	682	615
DD&A expenses	$ 1,713	$ 1,192	$ 1,031
DD&A - per unit of sales | $ / Unit	0	0	0
Asset impairment	$ 0	$ 0	$ 0
General and administrative	16,040	21,672	16,364
Loss from continuing operations before income taxes	(22,982)	(28,772)	(17,178)
Segment capital expenditures	$ 1,095	$ 2,868	$ 775

Segment and Geographic Report40

Segment and Geographic Reporting - Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Property, plant and equipment	$ 788,993	$ 1,128,944
Goodwill	102,581	102,581
All other assets	254,544	482,525
Total Assets	1,146,118	1,714,050
Operating Segments [Member] | Continuing Operations [Member] | Colombia [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment	574,351	888,822
Goodwill	102,581	102,581
All other assets	93,479	157,549
Total Assets	770,411	1,148,952
Operating Segments [Member] | Continuing Operations [Member] | Peru [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment	95,069	87,028
Goodwill	0	0
All other assets	21,111	40,613
Total Assets	116,180	127,641
Operating Segments [Member] | Continuing Operations [Member] | Brazil [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment	115,552	148,457
Goodwill	0	0
All other assets	2,236	14,724
Total Assets	117,788	163,181
All Other [Member] | Continuing Operations [Member] | All Other [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment	4,021	4,637
Goodwill	0	0
All other assets	137,718	269,639
Total Assets	$ 141,739	$ 274,276

Segment and Geographic Report41

Segment and Geographic Reporting - Narrative (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Ecopetrol [Member]
Concentration Risk [Line Items]
Sales to significant customers, as a percent (in hundredths)	43.00%	52.00%	46.00%
Customer Two [Member]
Concentration Risk [Line Items]
Sales to significant customers, as a percent (in hundredths)	15.00%	32.00%	42.00%
Customer Three [Member]
Concentration Risk [Line Items]
Sales to significant customers, as a percent (in hundredths)	13.00%
Customer Four [Member]
Concentration Risk [Line Items]
Sales to significant customers, as a percent (in hundredths)	12.00%

Accounts Receivable and Inven42

Accounts Receivable and Inventory (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 29,217	$ 83,227
Crude oil inventories	17,800	15,200
Supplies	1,300	2,100
Oil inventory impairment	2,633	0	$ 0
Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	26,924	80,058
Other Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 2,293	$ 3,169

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Cost	$ 2,337,443	$ 2,220,514
Accumulated depletion, depreciation and impairment	(1,548,450)	(1,091,570)
Total Property, Plant and Equipment	788,993	1,128,944
Proved [Member]
Property, Plant and Equipment [Line Items]
Cost	1,998,330	1,876,371
Unproved [Member]
Property, Plant and Equipment [Line Items]
Cost	310,771	316,856
Oil and natural gas properties [Member]
Property, Plant and Equipment [Line Items]
Cost	2,309,101	2,193,227
Furniture and Fixtures and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 28,342	$ 27,287

Property, Plant and Equipment44

Property, Plant and Equipment - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)block
Property, Plant and Equipment [Line Items]
Asset impairment	$ 323,918	$ 265,126	$ 2,000
Depletion and depreciation expense	177,900	187,900	194,200
Proceeds from sale of a blow-out preventer	0	0	55,524
Unproved assets by cost center	$ 310,800	316,900
Costs transferred to depletable base within 5 years	60.00%
Minimum [Member]
Property, Plant and Equipment [Line Items]
Transfer of costs to depletable base, period	5 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Transfer of costs to depletable base, period	10 years
Colombia [Member]
Property, Plant and Equipment [Line Items]
Asset impairment	$ 232,400
Unproved assets by cost center	147,500	170,500
Brazil [Member]
Property, Plant and Equipment [Line Items]
Asset impairment	46,900		2,000
Proceeds from termination of farm-in agreement			54,000
Unproved assets by cost center	69,100	60,700
Peru [Member]
Property, Plant and Equipment [Line Items]
Unproved assets by cost center	94,200	85,700
Block 95 [Member] | Peru [Member]
Property, Plant and Equipment [Line Items]
Asset impairment	$ 41,900	$ 265,100
Colombia [Member] | Mecaya Block [Member]
Property, Plant and Equipment [Line Items]
Proceeds from sale of a blow-out preventer			$ 1,500
Brazil [Member]
Property, Plant and Equipment [Line Items]
Number of blocks successfully bid | block			3
Payments for signature bonus			$ 14,400
Brazil and Colombia [Member]
Property, Plant and Equipment [Line Items]
Discount rate	10.00%

Property, Plant and Equipment45

Property, Plant and Equipment - Schedule of Asset Impairment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
Impairment of oil and gas properties	$ 321,285	$ 265,126	$ 2,000
Impairment of inventory	2,633	0	0
Asset impairment	$ 323,918	$ 265,126	$ 2,000

Property, Plant and Equipment46

Property, Plant and Equipment - Costs Incurred for Acquisition, Exploration and Development (Details) - USD ($) $ in Thousands	12 Months Ended			127 Months Ended	151 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2015
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Total oil and natural gas properties not subject to depletion	$ 30,305	$ 76,613	$ 42,183	$ 161,670	$ 310,771
Colombia [Member]
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Acquisition costs	0	0	0	67,597	67,597
Exploration costs	11,151	35,952	20,103	12,697	79,903
Peru [Member]
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Acquisition costs	0	0	0	21,147	21,147
Exploration costs	8,515	31,750	7,301	25,469	73,035
Brazil [Member]
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Acquisition costs	0	0	0	35,525	35,525
Exploration costs	$ 10,639	$ 8,911	$ 14,779	$ (765)	$ 33,564

Share Capital - Narrative (Deta

Share Capital - Narrative (Details)	1 Months Ended		12 Months Ended
	May. 31, 2013	Apr. 30, 2013	Dec. 31, 2015USD ($)vote$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)$ / sharesshares	Jul. 22, 2015shares	Jun. 27, 2012shares	Jun. 26, 2012shares
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Authorized share capital (in shares)			595,000,002
Common stock, shares authorized			570,000,000
Common shares, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001
Preferred stock, shares authorized			25,000,000
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.001
Special voting stock-authorized (in shares)			2
Special voting stock-par value (in dollars per share) | $ / shares			$ 0.001
Common shares, issued			273,442,799	276,072,351
Repurchase of shares of Common Stock | $			$ 9,999,000	$ 0	$ 0
Votes per common stock | vote			1
Common voting shares per exchangeable share (in shares)			1
Number of shares available for issuance under 2007 Equity Incentive Plan							39,806,100	23,306,100
Stock issued during period upon exercise of stock options (in shares)			390,000	3,029,853	1,306,317
Proceeds from issuance of shares of Common Stock | $			$ 722,000	$ 11,140,000	$ 3,771,000
Stock option exercises in period (in shares)			(390,000)
Weighted average contractual term of of outstanding stock options			3 years 3 months 18 days
Weighted average contractual term of exercisable options			2 years 8 months 12 days
Weighted average grant date fair value for options granted | $ / shares			$ 1.24	$ 2.47	$ 2.62
Weighted average grant date fair value for options vested (in dollars per share) | $ / shares			$ 2.38	$ 3.63	$ 3.94
Fair value of stock options vested | $			$ 6,800,000	$ 12,400,000	$ 12,400,000
Stock Options [Abstract]
Unvested stock options recognition period			1 year 6 months
Weighted average remaining contractual term			3 years 2 months 12 days
Stock Options [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Vesting period			3 years
Option term	5 years	10 years
Option term after leaving service of company	3 months	3 months
Stock Options [Abstract]
Unrecognized compensation cost related to unvested stock options | $			$ 3,900,000	$ 4,800,000
Earnings Per Share [Abstract]
Options excluded from the diluted income per share calculation			13,432,287	15,621,890	4,217,082
Restricted Stock Units (RSUs) [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Cash used to settle awards | $			$ 1,700,000	$ 3,400,000	$ 0
Common Stock [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares repurchased and canceled			4,567,136
Average purchase price (in dollars per share) | $ / shares			$ 2.19
Stock option exercises in period (in shares)			(390,000)
Gran Tierra Exchangeco Inc [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Exchangeable shares outstanding (in shares)			4,933,177
Gran Tierra Exchangeco Inc [Member] | Common Stock [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares repurchased and canceled			0
Stock option exercises in period (in shares)			0
Gran Tierra Goldstrike Inc [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Exchangeable shares outstanding (in shares)			3,638,889
Gran Tierra Goldstrike Inc [Member] | Common Stock [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares repurchased and canceled			0
Stock option exercises in period (in shares)			0
2015 Program [Member] | Common Stock [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Number of common shares authorized to be repurchased (up to)						13,831,866
Percent of issued and outstanding common shares authorized to be be repurchased						4.98%

Share Capital - Schedule of Com

Share Capital - Schedule of Common Stock (Details)	12 Months Ended
	Dec. 31, 2015shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance	276,072,351
Options exercised	390,000
Ending balance	273,442,799
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance	276,072,351
Options exercised	390,000
Shares repurchased and canceled	(4,567,136)
Exchange of exchangeable shares	1,547,595
Shares canceled	(11)
Ending balance	273,442,799
Gran Tierra Exchangeco Inc [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance	5,595,118
Options exercised	0
Shares repurchased and canceled	0
Exchange of exchangeable shares	(661,857)
Shares canceled	(84)
Ending balance	4,933,177
Gran Tierra Goldstrike Inc [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance	4,524,627
Options exercised	0
Shares repurchased and canceled	0
Exchange of exchangeable shares	(885,738)
Shares canceled	0
Ending balance	3,638,889

Share Capital - Black Scholes O

Share Capital - Black Scholes Option Pricing Model Assumptions (Details) - Stock Options [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend rate for fair value assumption	0.00%	0.00%	0.00%
Expected volatility rate for fair value assumption, minimum	46.00%	39.00%	42.00%
Expected volatility rate for fair value assumption, maximum	50.00%	42.00%	54.00%
Weighted average volatility fair value assumption	48.00%	41.00%	53.00%
Risk free interest rate for fair value assumption, minimum	1.20%	0.78%	0.30%
Risk free interest rate for fair value assumption, maximum	1.70%	1.45%	0.70%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term for fair value assumption	4 years	4 years	4 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term for fair value assumption	5 years	5 years	5 years

Share Capital - RSU and Stock O

Share Capital - RSU and Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Number of Outstanding Options
Balance, Beginning of period (in shares)	13,790,220
Granted (in shares)	5,346,260
Exercised (in shares)	(390,000)
Forfeited (in shares)	(1,394,445)
Expired (in shares)	(4,500,478)
Balance, End of period (in shares)	12,851,557
Exercisable, at end of period (in shares)	7,784,678
Vested, or expected to vest, at end of period through the life of the options (in shares)	12,494,309
Weighted Average Exercise Price $/Option
Weighted Average Exercise Price $/Option, beginning balance (in dollars per share) | $ / shares	$ 5.93
Weighted Average Exercise Price $/Option, Granted (in dollars per share) | $ / shares	3.08
Weighted Average Exercise Price $/Options Exercised (in dollars per share) | $ / shares	1.85
Weighted Average Exercise Price $/Options, Forfeited (in dollars per share) | $ / shares	(5.63)
Weighted Average Exercise Price $/Options, Expired (in dollars per share) | $ / shares	(6.78)
Weighted Average Exercise Price $/Option, ending balance (in dollars per share) | $ / shares	4.60
Weighted Average Exercise Price $/Option, Exercisable, at end of period | $ / shares	5.17
Weighted Average Exercise Price $/Option, Vested, or expected to vest, at end of period through the life of the options | $ / shares	$ 4.63
Restricted Stock Units (RSUs) [Member]
Number of Outstanding Share Units
Balance, Beginning of period (in shares)	1,236,963
Granted (in shares)	1,041,450
Exercised (in shares)	(531,012)
Forfeited (in shares)	(731,944)
Expired (in shares)	0
Balance, End of period (in shares)	1,015,457

Share Capital - Allocation of S

Share Capital - Allocation of Share Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 2,892	$ 9,535	$ 11,354
Less: Stock-based compensation costs capitalized	(159)	(1,815)	(2,436)
Stock-based compensation costs expensed	2,733	7,720	8,918
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	2,263	6,976	8,418
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 629	$ 2,559	$ 2,936

Share Capital - Weighted Averag

Share Capital - Weighted Average Shares (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average number of common and exchangeable shares outstanding	285,333,869	284,715,785	282,808,497
Shares issuable pursuant to stock options	0	0	12,041,260
Shares assumed to be purchased from proceeds of stock options	0	0	(8,721,860)
Weighted average number of diluted common and exchangeable shares outstanding	285,333,869	284,715,785	286,127,897

Asset Retirement Obligation (De

Asset Retirement Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance, beginning of year	$ 35,812	$ 21,973
Settlements	(6,317)	(1,137)
Liability incurred	1,556	11,956
Liabilities associated with the Argentina business unit sold	0	(10,170)
Accretion	1,313	1,406
Revisions in estimated liability	860	11,784
Balance, end of year	33,224	35,812	$ 21,973
Asset retirement obligation - current	2,146	8,026
Asset retirement obligation - long-term	31,078	27,786
Cash settlement of asset retirement obligation	(6,217)	(796)	$ (2,068)
Fair value of legally restricted assets	$ 2,900	2,000
Peru [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Revisions in estimated liability		$ 7,600

Taxes - Income Tax Reconciliati

Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
(Loss) income from continuing operations before income taxes
United States	$ (14,061)	$ (19,744)	$ (13,566)
Foreign	(354,027)	2,610	322,850
(LOSS) INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	$ (368,088)	$ (17,134)	$ 309,284
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Effective income tax rate	35.00%	35.00%	35.00%
Income tax (recovery) expense from continuing operations expected	$ (128,831)	$ (5,997)	$ 108,249
Foreign currency translation adjustments	(187)	(6,520)	(7,185)
Impact of foreign taxes	(13,087)	27,910	(3,596)
Other local taxes	2,354	4,433	3,673
Stock-based compensation	919	2,232	2,724
Increase in valuation allowance	37,691	94,922	21,423
Non-deductible third party royalty in Colombia	3,416	9,116	11,073
Other permanent differences	(2,334)	1,119	(8,100)
Total income tax (recovery) expense from continuing operations	(100,059)	127,215	128,261
Current income tax expense from continuing operations
United States	1,070	1,260	1,250
Foreign	14,313	91,605	155,876
Total Current income tax expense	15,383	92,865	157,126
Deferred income tax (recovery) expense from continuing operations
Foreign	(115,442)	34,350	(28,865)
Income tax rate reconciliation, tax basis and loss adjustments			7,400
Income tax rate reconciliation, tax basis and loss adjustments offset by change in valuation allowance			$ 5,000
National Taxes and Customs Direction (DIAN) [Member] | Foreign Tax Authority [Member]
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Impact of foreign taxes	11,800	$ 28,100
Deferred income tax (recovery) expense from continuing operations
Deferred tax recovery associated with ceiling test impairment	$ 91,700

Taxes - Permanent Differences R

Taxes - Permanent Differences Reconciliation (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Tax benefit of operating loss carryforwards	$ 56,015	$ 51,248
Tax basis in excess of book basis	139,012	108,120
Foreign tax credits and other accruals	22,674	20,369
Tax benefit of capital loss carryforwards	30,799	29,984
Deferred tax assets before valuation allowance	248,500	209,721
Valuation allowance	(245,259)	(207,568)
Deferred tax assets, net	3,241	2,153
Deferred tax liabilities	34,592	176,364
Net Deferred Tax Liabilities	$ (31,351)	$ (174,211)

Taxes - Changes in Unrecognized

Taxes - Changes in Unrecognized Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit relating to loss or income from continuing operations, beginning of year	$ 3,300	$ 2,900	$ 5,900
Increases for positions relating to prior year	0	500	0
Decreases for positions relating to prior year	(800)	(100)	(3,000)
Decreases due to lapse of statute of limitations	(300)	0	0
Unrecognized tax benefit relating to loss or income from continuing operations, end of year	$ 2,200	$ 3,300	$ 2,900

Taxes - Narrative (Details)

Taxes - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Valuation Allowance [Line Items]
Operating loss carryforwards	$ 178,700,000			$ 178,700,000	$ 167,000,000
Capital losses before valuation allowance	228,100,000			228,100,000	232,200,000
Net operating loss carryforward from foreign subsidiaries	355,900,000			355,900,000	356,100,000
Increase in valuation allowance				37,700,000
Unrecognized tax benefits	2,200,000			2,200,000	3,300,000	$ 2,900,000	$ 5,900,000
Unrecognized income tax penalties and interest accrued	1,400,000			1,400,000	2,000,000
Unrecognized tax benefit included in income tax expense (recovery)				$ (600,000)	400,000	(2,100,000)
Equity tax rates		0.40%	1.00%	1.15%
Equity tax				$ 3,769,000	0	$ 0
Equity taxes payable	$ 0			0	$ 0
Colombia [Member]
Valuation Allowance [Line Items]
Increase in deferred tax liability				$ 31,000,000
Colombia [Member] | Tax Year 2015 [Member]
Valuation Allowance [Line Items]
CREE surtax rate	5.00%
Consolidated income tax rate, CREE tax and surtax, combined (percent)	39.00%
Colombia [Member] | Tax Year 2016 [Member]
Valuation Allowance [Line Items]
CREE surtax rate	6.00%
Consolidated income tax rate, CREE tax and surtax, combined (percent)	40.00%
Colombia [Member] | Tax Year 2017 [Member]
Valuation Allowance [Line Items]
CREE surtax rate	8.00%
Consolidated income tax rate, CREE tax and surtax, combined (percent)	42.00%
Colombia [Member] | Tax Year 2018 [Member]
Valuation Allowance [Line Items]
CREE surtax rate	9.00%
Consolidated income tax rate, CREE tax and surtax, combined (percent)	43.00%
Colombia [Member] | Tax Year 2019 and Thereafter [Member]
Valuation Allowance [Line Items]
Foreign income tax rate	34.00%

Accounts Payable and Accrued 58

Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Trade	$ 54,402	$ 148,998
Royalties	2,066	10,788
VAT and withholding tax	818	8,573
Employee compensation and severance	8,414	10,900
Other	5,078	8,572
Total	$ 70,778	$ 187,831

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Thousands, bbl in Millions	Apr. 30, 2015bbl	Dec. 31, 2015USD ($)	Dec. 31, 2015USD ($)bbl	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Loss Contingencies [Line Items]
Rent expense			$ 4,000	$ 3,200	$ 3,100
Notes payable provided as security for letter of credit		$ 76,500	76,500	86,300
Gain on litigation settlement			502	$ 2,000	$ 0
Pending Litigation Moqueta Discovery [Member]
Loss Contingencies [Line Items]
Value of damages sought for loss contingency			66,300
Related interest costs			26,500
Related interest			$ 6,400
Threshold by which additional royalty due (barrels) | bbl			5
Total cumulative production of oil field (barrels) | bbl	5
Pending Litigation Royalty, Transportation and Related Costs [Member] [Member]
Loss Contingencies [Line Items]
Royalty agreement, spread on peso denominated debt		29.00%	29.00%
Pending Litigation Moqueta Discovery, Transportation and Related Costs [Member]
Loss Contingencies [Line Items]
Value of damages sought for loss contingency			$ 44,800
Legal Dispute, Oil [Member]
Loss Contingencies [Line Items]
Amount awarded by the appeal court		$ 1,900
Gain on litigation settlement			$ 502
Three Month LIBOR [Member] | Pending Litigation Royalty, Transportation and Related Costs [Member] [Member]
Loss Contingencies [Line Items]
Royalty agreement, spread on U.S. dollar denominated debt		4.00%	4.00%

Commitments and Contingencies60

Commitments and Contingencies - Schedule of Contractual Obligations Future Lease Payments (Details) $ in Thousands	Dec. 31, 2015USD ($)
Unrecorded Unconditional Purchase Obligation [Line Items]
Total	$ 33,632
2,016	10,022
2,017	9,082
2,018	7,016
2,019	3,641
2,020	3,640
Thereafter	231
Oil transportation services [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Total	18,441
2,016	3,650
2,017	3,640
2,018	3,640
2,019	3,640
2,020	3,640
Thereafter	231
Drilling, Completions and Seismic [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Total	7,572
2,016	2,918
2,017	2,667
2,018	1,987
2,019	0
2,020	0
Thereafter	0
Operating leases [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Total	7,140
2,016	3,103
2,017	2,647
2,018	1,389
2,019	1
2,020	0
Thereafter	0
Software and telecommunication [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Total	479
2,016	351
2,017	128
2,018	0
2,019	0
2,020	0
Thereafter	$ 0

Financial Instruments, Fair V61

Financial Instruments, Fair Value Measurement, Credit Risk and Foreign Exchange Risk - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)customer	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign exchange losses, Colombian peso to U.S. dollar | $	$ 10
Colombia [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage of revenues denominated in United States dollars	100.00%
Number of major customers	4
Colombia [Member] | Geographic Concentration Risk [Member] | Sales Revenue, Segment [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Concentration risk, percentage	97.00%	95.00%	96.00%
Brazil [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of significant customers	1
Block-Brazil [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Participating interest percentage oil and gas property, remaining percentage	30.00%

Financial Instruments, Fair V62

Financial Instruments, Fair Value Measurement, Credit Risk and Foreign Exchange Risk - Fair Value of Trading Securities, Foreign Currency Derivative Liability and Contingent Consideration (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Trading securities	$ 6,250	$ 7,586
Foreign currency derivative liability	0	3,057
Contingent consideration liability	1,061	1,061
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 1,061	$ 4,118

Financial Instruments, Fair V63

Financial Instruments, Fair Value Measurement, Credit Risk and Foreign Exchange Risk - Gains Recognized in the Statement of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Trading securities loss	$ 1,335	$ 6,326	$ 0
Foreign currency derivatives loss (gain)	692	(1,604)	0
Loss (gain) on Investments and Derivative Instruments, Net, Pretax	$ 2,027	$ 4,722	$ 0

Severance Expenses - Expenses b

Severance Expenses - Expenses by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Severance expenses	$ 8,990	$ 0	$ 0
Operating Segments [Member] | Colombia [Member]
Restructuring Cost and Reserve [Line Items]
Severance expenses	1,837
Operating Segments [Member] | Peru [Member]
Restructuring Cost and Reserve [Line Items]
Severance expenses	2,096
Operating Segments [Member] | Brazil [Member]
Restructuring Cost and Reserve [Line Items]
Severance expenses	374
All Other [Member]
Restructuring Cost and Reserve [Line Items]
Severance expenses	$ 4,683

Severance Expenses - Change in

Severance Expenses - Change in Severance Expense Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$ 0
Liability incurred	8,990	$ 0	$ 0
Settlements	(7,526)
Balance, end of period	$ 1,464	$ 0

Credit Facility (Details)

Credit Facility (Details)	12 Months Ended
	Dec. 31, 2015USD ($)Subsidiary
Line of Credit Facility [Line Items]
Number of subsidiaries used as collateral for reserve based facility | Subsidiary	2
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Current borrowing capacity	$ 200,000,000
Maximum borrowing capacity (up to)	$ 500,000,000
Stand-by fee on unutilized balance	0.75%
Amounts drawn on facility	$ 0
Revolving Credit Facility [Member] | Minimum [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.00%
Revolving Credit Facility [Member] | Minimum [Member] | Alternate Base Rate [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.00%
Revolving Credit Facility [Member] | Maximum [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	3.00%
Revolving Credit Facility [Member] | Maximum [Member] | Alternate Base Rate [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.00%
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity (up to)	$ 100,000,000
Stand-by fee on unutilized balance	0.25%

Supplemental Cash Flow Inform67

Supplemental Cash Flow Information - Net Changes in Assets and Liabilities from Operating Activities of Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Elements [Abstract]
Accounts receivable and other long-term assets	$ 44,365	$ (34,473)	$ 58,955
Inventory	(1,571)	(2,891)	14,168
Prepaids	152	4	(2,458)
Accounts payable and accrued and other long-term liabilities	(34,493)	558	(8,754)
Taxes receivable and payable	(48,251)	(61,064)	84,687
Net changes in assets and liabilities from operating activities of continuing operations	$ (39,798)	$ (97,866)	$ 146,598

Supplemental Cash Flow Inform68

Supplemental Cash Flow Information - Additional Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Elements [Abstract]
Cash paid for income taxes	$ 39,422	$ 101,179	$ 51,183
Net liabilities related to property, plant and equipment, end of year	33,923	113,874	75,580
Acquisition of marketable securities as proceeds from sale of Argentina business unit	$ 0	$ 13,912	$ 0

Subsequent events (Details)

Subsequent events (Details) - Subsequent Event [Member] $ / shares in Units, $ in Millions	Jan. 25, 2016USD ($)bbl	Jan. 13, 2016USD ($)$ / sharesshares	Jan. 13, 2016CAD / shares
Petroamerica [Member]
Subsequent Event [Line Items]
Cash transferred (per share) | CAD / shares			CAD 1.33
Cash paid for acquisition		$ 70.6
Net purchase price	$ 19	70.4
Net working capital		26
Total consideration		$ 96.4
Petroamerica [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Shares issued in acquisition (in shares) | shares		13,656,719
Common shares, par value (in dollars per share) | $ / shares		$ 0.001
Fair value of common stock issued		$ 25.8
PetroGranda Colombia Limited [Member]
Subsequent Event [Line Items]
Net working capital	18.7
Petroamerica [Member]
Subsequent Event [Line Items]
Noncontrolling interest percentage ownership		4.60%
Gran Tierra Energy Inc. [Member]
Subsequent Event [Line Items]
Percentage ownership		95.40%
Common Stock [Member] | Petroamerica [Member]
Subsequent Event [Line Items]
Shares of Gran Tierra per share of Petroamerica | shares		0.40
Cumulative Production under Putumayo Block [Member] | Petroamerica [Member]
Subsequent Event [Line Items]
Contingent consideration	$ 4
Volume threshold (exceeds) | bbl	8,000,000