Gran Tierra Energy (GTE) 10-Q 8 Aug 16 2016 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2016	Aug. 02, 2016
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 Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		289,322,888
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2016

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
OIL AND NATURAL GAS SALES (NOTE 4)	$ 71,713	$ 69,350	$ 129,116	$ 145,581
EXPENSES
Operating	17,748	17,758	36,815	40,419
Transportation	6,217	6,375	18,545	15,148
Depletion, depreciation and accretion (Note 4)	31,884	39,188	68,796	88,328
Asset impairment (Notes 4 and 5)	92,843	30,285	149,741	67,299
General and administrative (Note 4)	7,975	10,298	16,261	17,592
Severance	281	1,988	1,299	6,366
Equity tax (Note 9)	0	0	3,051	3,769
Foreign exchange loss (gain)	781	2,969	1,566	(8,569)
Financial instruments gain (Note 12)	(1,072)	(1,366)	(227)	(1,408)
Total expenses	156,657	107,495	295,847	228,944
GAIN ON ACQUISITION (NOTE 3)	0	0	11,712	0
INTEREST EXPENSE (NOTE 6)	(2,201)	0	(2,720)	0
INTEREST INCOME	749	382	1,198	803
LOSS BEFORE INCOME TAXES (NOTE 4)	(86,396)	(37,763)	(156,541)	(82,560)
INCOME TAX (EXPENSE) RECOVERY
Current	(5,778)	(5,684)	(7,801)	(8,109)
Deferred	28,615	4,883	55,751	7,239
Income tax (expense) recovery	22,837	(801)	47,950	(870)
NET LOSS AND COMPREHENSIVE LOSS	$ (63,559)	$ (38,564)	$ (108,591)	$ (83,430)
NET LOSS PER SHARE - BASIC AND DILUTED (in dollars per share)	$ (0.21)	$ (0.13)	$ (0.37)	$ (0.29)
WEIGHTED AVERAGE SHARES OUTSTANDING - BASIC AND DILUTED (Note 7)	296,565,530	286,393,772	295,188,878	286,294,595

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 171,470	$ 145,342
Restricted cash (Notes 3 and 5)	9,716	92
Accounts receivable	43,733	29,217
Marketable securities (Note 12)	3,979	6,250
Derivatives (Note 12)	7,014	0
Inventory (Note 5)	9,339	19,056
Taxes receivable	30,387	28,635
Other current assets	5,112	5,848
Total Current Assets	280,750	234,440
Oil and Gas Properties
Proved	372,752	469,589
Unproved	366,079	310,771
Total Oil and Gas Properties	738,831	780,360
Other capital assets	8,432	8,633
Total Property, Plant and Equipment (Notes 4 and 5)	747,263	788,993
Other Long-Term Assets
Restricted cash	6,750	3,317
Taxes receivable	9,497	8,276
Other long-term assets	15,578	8,511
Goodwill (Note 4)	102,581	102,581
Total Other Long-Term Assets	134,406	122,685
Total Assets	1,162,419	1,146,118
Current Liabilities
Accounts payable and accrued liabilities	65,850	70,778
Taxes payable	1,115	1,067
Asset retirement obligation (Note 8)	2,970	2,146
Total Current Liabilities	69,935	73,991
Long-Term Liabilities
Convertible senior notes (Notes 6 and 12)	109,145	0
Deferred tax liabilities	5,552	34,592
Asset retirement obligation (Note 8)	40,870	31,078
Other long-term liabilities	10,921	4,815
Total Long-Term Liabilities	166,488	70,485
Contingencies (Note 11)
Shareholders’ Equity
Common Stock (Note 7) (289,322,888 and 273,442,799 shares of Common Stock and 8,514,066 and 8,572,066 exchangeable shares, par value $0.001 per share, issued and outstanding as at June 30, 2016, and December 31, 2015, respectively)	10,202	10,186
Additional paid in capital	1,052,792	1,019,863
Deficit	(136,998)	(28,407)
Total Shareholders’ Equity	925,996	1,001,642
Total Liabilities and Shareholders’ Equity	$ 1,162,419	$ 1,146,118

Condensed Consolidated Balance4

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common shares, issued	289,322,888	273,442,799
Common shares, outstanding	289,322,888	273,442,799
Exchangeable shares, issued	8,514,066	8,572,066
Exchangeable shares, outstanding	8,514,066	8,572,066
Common shares, par value (in dollars per share)	$ 0.001	$ 0.001

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Operating Activities
Net loss	$ (108,591)	$ (83,430)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depletion, depreciation and accretion (Note 4)	68,796	88,328
Asset impairment (Notes 4 and 5)	149,741	67,299
Deferred tax recovery	(55,751)	(7,239)
Stock-based compensation expense (Note 7)	3,522	1,113
Amortization of debt issuance costs (Note 6)	629	0
Cash settlement of restricted share units	(1,186)	(1,314)
Unrealized foreign exchange loss (gain)	50	(5,564)
Financial instruments gain (Note 12)	(227)	(1,408)
Cash settlement of financial instruments	47	(3,749)
Cash settlement of asset retirement obligation (Note 8)	(464)	(1,964)
Gain on acquisition (Note 3)	(11,712)	0
Net change in assets and liabilities from operating activities (Note 13)	(6,630)	(46,504)
Net cash provided by operating activities	38,224	5,568
Investing Activities
Increase in restricted cash	(2,349)	(320)
Additions to property, plant and equipment, excluding Corporate acquisition (Note 4)	(44,587)	(91,318)
Additions to property, plant and equipment - acquisition of PetroGranada Colombia Limited (Note 5)	(19,388)	0
Changes in non-cash investing working capital	(11,059)	(77,109)
Cash paid for business combination, net of cash acquired (Note 3)	(50,909)	0
Net cash used in investing activities	(128,292)	(168,747)
Financing Activities
Proceeds from issuance of the Notes, net of issuance costs (Note 6)	108,900	0
Proceeds from issuance of shares of Common Stock (Note 7)	5,350	602
Net cash provided by financing activities	114,250	602
Foreign exchange gain (loss) on cash and cash equivalents	1,946	(2,872)
Net increase (decrease) in cash and cash equivalents	26,128	(165,449)
Cash and cash equivalents, beginning of period	145,342	331,848
Cash and cash equivalents, end of period	$ 171,470	$ 166,399

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Share Capital	Additional Paid in Capital	Retained Earnings (Deficit)
Beginning balance at Dec. 31, 2014		$ 10,190	$ 1,026,873	$ 239,622
Increase (Decrease) in Stockholders' Equity
Issuance of Common Stock (Note 7)		0	0
Exercise of stock options (Note 7)			722
Stock-based compensation (Note 7)			2,263
Repurchase of Common Stock		(4)	(9,995)
Net loss				(268,029)
Ending balance at Dec. 31, 2015	$ 1,001,642	10,186	1,019,863	(28,407)
Increase (Decrease) in Stockholders' Equity
Issuance of Common Stock (Note 7)		16	25,798
Exercise of stock options (Note 7)			5,347
Stock-based compensation (Note 7)			1,784
Repurchase of Common Stock		0	0
Net loss	(108,591)			(108,591)
Ending balance at Jun. 30, 2016	$ 925,996	$ 10,202	$ 1,052,792	$ (136,998)

Description of Business

Description of Business	6 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Gran Tierra Energy Inc., a Nevada corporation (the “Company” or “Gran Tierra”), is a publicly traded company focused on oil and natural gas exploration and production in Colombia. The Company also has business activities in Peru and Brazil.

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies These interim unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The information furnished herein reflects all normal recurring adjustments that are, in the opinion of management, necessary for the fair presentation of results for the interim periods. The note disclosure requirements of annual consolidated financial statements provide additional disclosures to that required for interim unaudited condensed consolidated financial statements. Accordingly, these interim unaudited condensed consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements as at and for the year ended December 31, 2015 , included in the Company’s 2015 Annual Report on Form 10-K, filed with the SEC on February 29, 2016 . The Company’s significant accounting policies are described in Note 2 of the consolidated financial statements which are included in the Company’s 2015 Annual Report on Form 10-K and are the same policies followed in these interim unaudited condensed consolidated financial statements, except as noted below. The Company has evaluated all subsequent events through to the date these interim unaudited condensed consolidated financial statements were issued. Convertible Senior Notes The Company accounts for its 5.00% Convertible Senior Notes due 2021 (the "Notes") as a liability in their entirety. The embedded features of the Notes were assessed for bifurcation from the Notes under the applicable provisions, including the basic conversion feature, the fundamental change make-whole provision and the put and call options. Based on an assessment, the Company concluded that these embedded features did not meet the criteria to be accounted for separately. The Company incurred debt issuance costs in connection with the issuance of the Notes which have been presented as a direct deduction against the carrying amount of the Notes and are being amortized to interest expense using the effective interest method over the contractual term of the Notes. Derivatives The Company's commodity price and foreign currency derivatives are recorded on its interim unaudited condensed consolidated balance sheet at fair value as either an asset or a liability with changes in fair value recognized in the interim unaudited condensed consolidated statements of operations. While the Company utilizes derivative instruments to manage the price risk attributable to its expected oil production and foreign exchange risk, it has elected not to designate its derivative instruments as accounting hedges under the accounting guidance. Recently Issued Accounting Pronouncements Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (the "FASB") issued guidance regarding the accounting for revenue from contracts with customers. In August 2015, the FASB issued Accounting Standards Update (“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. In March 2016, the FASB issued ASU 2016-08, “Principal versus Agent Considerations (Reporting Revenue Gross versus Net)" which clarifies implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU 2016-10, “Identifying Performance Obligations and Licensing" which clarifies implementation guidance. In May 2016, the FASB issued ASU 2016-12, “Narrow-Scope Improvements and Practical Expedients" which reduces the potential for diversity in practice at initial application and the cost and complexity of applying Topic 606 both at transition and on an ongoing basis. The Company is currently assessing the impact the new revenue recognition model will have on its consolidated financial position, results of operations, cash flows, and disclosure. Simplifying the Accounting for Measurement - Period Adjustments In September 2015, the FASB issued ASU 2015-16, "Simplifying the Accounting for Measurement - Period Adjustments". The amendments require that an acquirer recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which the adjustments are determined and eliminates the requirement to retrospectively revise prior periods. Additionally, an acquirer should record in the same period the effects on earnings of any changes in the provisional accounts, calculated as if the accounting had been completed at the acquisition date. The ASU was effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. 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. Leases In February 2016, the FASB issued ASU 2016-02, “Leases". This ASU will require most lease assets and lease liabilities to be recognized on the balance sheet and the disclosure of key information about lease arrangements. The ASU will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. The Company is currently assessing the impact the new lease standard will have on its consolidated financial position, results of operations, cash flows, and disclosure. Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting ". This ASU simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for forfeitures, income taxes, and statutory tax withholding requirements. The ASU will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The Company is currently assessing the impact this update will have on its consolidated financial position, results of operations, cash flows, and disclosure.

Business Combination

Business Combination	6 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
Business Combination	Business Combination 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”). 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, each Petroamerica shareholder was entitled to receive, for each Petroamerica share held, either 0.40 of a Gran Tierra common share or $1.33 Canadian dollars in cash, or a combination of shares and cash, subject to a maximum of 70% of the consideration payable in cash. As consideration for the acquisition of all the issued and outstanding Petroamerica shares, the Company issued approximately 13.7 million shares of Gran Tierra Common Stock, par value $0.001 , and paid cash consideration of approximately $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 $72.2 million , after giving consideration to net working capital of $24.2 million . Upon completion of the transaction on the Petroamerica Acquisition Date, Petroamerica became an indirect wholly-owned subsidiary of Gran Tierra. The acquisition was accounted for as a business combination using the acquisition method, with Gran Tierra being the acquirer, whereby the assets acquired and liabilities assumed were recognized at their fair values as at the Petroamerica Acquisition Date, and the results of Petroamerica were included with those of Gran Tierra from that date. Fair value estimates were made based on significant unobservable (Level 3) inputs and based on the best information available at the time. The following table shows the allocation of the consideration transferred based on the fair values of the assets and liabilities acquired: (Thousands of U.S. Dollars) Consideration Transferred: Cash $ 70,625 Shares of Common Stock issued net of share issue costs 25,811 $ 96,436 Allocation of Consideration Transferred (1) : Oil and gas properties Proved $ 48,595 Unproved 50,054 Net working capital (including cash acquired of $19.7 million, restricted cash of $2.5 million and accounts receivable of $5.0 million) 24,202 Long-term restricted cash 8,167 Other long-term assets 1,570 Long-term deferred tax liability (10,105 ) Long-term portion of asset retirement obligation (11,556 ) Other long-term liabilities (2,779 ) Gain on acquisition (11,712 ) $ 96,436 (1) The allocation of the consideration transferred is incomplete and is subject to change. Management is continuing to review and assess information to accurately determine the acquisition date fair value of the assets and liabilities acquired. During the measurement period, Gran Tierra will continue to obtain information to assist in finalizing the fair value of net assets acquired, which may differ materially from the above preliminary estimates. As indicated in the allocation of the consideration transferred, the fair value of identifiable assets acquired and liabilities assumed exceeded the fair value of the consideration transferred. Consequently, Gran Tierra reassessed the recognition and measurement of identifiable assets acquired and liabilities assumed and concluded that all acquired assets and assumed liabilities were recognized and that the valuation procedures and resulting measures were appropriate. As a result, Gran Tierra recognized a “Gain on acquisition” of $11.7 million in the interim unaudited condensed consolidated statement of operations for the six months ended June 30, 2016 . The gain reflects the impact on Petroamerica’s pre-acquisition market value resulting from the company's lack of liquidity and capital resources required to maintain current production and reserves and further develop and explore their inventory of prospects. Pro Forma Results (unaudited) Pro forma results for the six months ended June 30, 2016 and 2015, are shown below, as if the acquisition had occurred on January 1, 2015. Pro forma results are not indicative of actual results or future performance. Six Months Ended June 30, (Unaudited, thousands of U.S. Dollars, except per share amounts) 2016 2015 Oil and gas sales $ 129,587 $ 178,509 Net loss $ (120,317 ) $ (138,535 ) Net loss per share - basic and diluted $ (0.41 ) $ (0.48 ) The supplemental pro forma net loss of Gran Tierra for the six months ended June 30, 2016 , was adjusted to exclude the $11.7 million gain on acquisition and $1.3 million of acquisition costs recorded in general and administrative ("G&A") expenses because they were not expected to have a continuing impact on Gran Tierra’s results of operations. The Company's consolidated statement of operations for the six months ended June 30, 2016 , included oil and gas sales of $8.9 million and a loss after tax of $18.2 million from Petroamerica for the period subsequent to the Petroamerica Acquisition Date.

Segment and Geographic Reportin

Segment and Geographic Reporting	6 Months Ended
	Jun. 30, 2016
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 before income taxes. The following tables present information on the Company’s reportable segments and other activities: Three Months Ended June 30, 2016 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 69,271 $ — $ 2,442 $ — $ 71,713 Depletion, depreciation and accretion 30,458 71 1,024 331 31,884 Asset impairment 78,208 483 14,152 — 92,843 General and administrative expenses 4,430 387 241 2,917 7,975 Loss before income taxes (64,836 ) (744 ) (14,037 ) (6,779 ) (86,396 ) Segment capital expenditures 14,535 1,102 2,160 610 18,407 Three Months Ended June 30, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 67,627 $ — $ 1,723 $ — $ 69,350 Depletion, depreciation and accretion 37,061 147 1,575 405 39,188 Asset impairment — 5,285 25,000 — 30,285 General and administrative expenses 3,035 1,273 965 5,025 10,298 Income (loss) before income taxes 3,197 (8,261 ) (28,211 ) (4,488 ) (37,763 ) Segment capital expenditures 8,173 6,878 2,505 316 17,872 Six Months Ended June 30, 2016 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 125,571 $ — $ 3,545 $ — $ 129,116 Depletion, depreciation and accretion 66,194 212 1,742 648 68,796 Asset impairment 133,440 899 15,402 — 149,741 General and administrative expenses 7,695 796 533 7,237 16,261 Loss before income taxes (137,557 ) (1,456 ) (15,546 ) (1,982 ) (156,541 ) Segment capital expenditures (1) 36,522 2,369 4,880 816 44,587 Six Months Ended June 30, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 141,694 $ — $ 3,887 $ — $ 145,581 Depletion, depreciation and accretion 83,316 414 3,836 762 88,328 Asset impairment — 37,966 29,333 — 67,299 General and administrative expenses 5,751 2,313 1,592 7,936 17,592 Income (loss) before income taxes 6,125 (43,703 ) (35,092 ) (9,890 ) (82,560 ) Segment capital expenditures 29,295 44,577 16,411 1,035 91,318 (1) On January 13, 2016, the Company acquired all of the issued and outstanding common shares of Petroamerica, which acquisition was accounted for as a business combination (Note 3) and, therefore, property, plant and equipment acquired are not reflected in the table above. Additionally, on January 25, 2016, the Company acquired all of the issued and outstanding common shares of PetroGranada Colombia Limited ("PGC"), which acquisition was accounted for as an asset acquisition (Note 5) and property, plant and equipment acquired in this acquisition are not reflected in the table above. As at June 30, 2016 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Property, plant and equipment $ 543,273 $ 96,433 $ 103,368 $ 4,189 $ 747,263 Goodwill 102,581 — — — 102,581 All other assets 146,191 16,404 3,211 146,769 312,575 Total Assets $ 792,045 $ 112,837 $ 106,579 $ 150,958 $ 1,162,419 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

Property, Plant and Equipment a

Property, Plant and Equipment and Inventory	6 Months Ended
	Jun. 30, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment and Inventory	Property, Plant and Equipment and Inventory Property, Plant and Equipment (Thousands of U.S. Dollars) As at June 30, 2016 As at December 31, 2015 Oil and natural gas properties Proved $ 2,111,268 $ 1,998,330 Unproved 366,079 310,771 2,477,347 2,309,101 Other 28,597 28,342 2,505,944 2,337,443 Accumulated depletion, depreciation and impairment (1,758,681 ) (1,548,450 ) $ 747,263 $ 788,993 In the three and six months ended June 30, 2016 , the Company recorded ceiling test impairment losses in its Colombia cost center of $78.2 million and $132.8 million , respectively, and in its Brazil cost center of $14.2 million and $15.4 million , respectively, related to lower oil prices. In the three and six months ended June 30, 2015 , the Company recorded ceiling test impairment losses in its Brazil cost center of $25.0 million and $29.3 million , 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 three and six months ended June 30, 2016 , and 2015 , the Company recorded impairment losses in its Peru cost center of $0.5 million and $0.9 million and $5.3 million and $38.0 million , respectively, related to costs incurred on Block 95. Asset impairment for the three and six months ended June 30, 2016 , and 2015 was as follows: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Impairment of oil and gas properties $ 92,843 $ 30,285 $ 149,077 $ 67,299 Impairment of inventory — — 664 — $ 92,843 $ 30,285 $ 149,741 $ 67,299 Acquisition of PGC On January 25, 2016, the Company acquired all of the issued and outstanding common shares of PGC, pursuant to the terms and conditions of an acquisition agreement dated January 14, 2016. Upon completion of the transaction, PGC became an indirect wholly-owned subsidiary of Gran Tierra. The net purchase price of PGC was $19.4 million , after giving consideration to net working capital of $18.3 million . The acquisition was accounted for as an asset acquisition with the excess consideration transferred over the fair value of the net assets acquired allocated on a relative fair value basis to the net assets acquired. The following table shows the allocation of the cost of the acquisition based on the relative fair values of the assets and liabilities acquired: (Thousands of U.S. Dollars) Cost of asset acquisition: Cash $ 37,727 Allocation of Consideration Transferred: Oil and gas properties Proved $ 12,228 Unproved 15,563 27,791 Net working capital (including cash acquired of $0.2 million and restricted cash of $18.6 million) 18,339 Long-term deferred tax liability (8,403 ) $ 37,727 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. Contingent consideration will be recognized when the contingency is resolved. Inventory At June 30, 2016 , oil and supplies inventories were $8.0 million and $1.3 million , respectively ( December 31, 2015 - $17.8 million and $1.3 million , respectively). At June 30, 2016 , the Company had 244 Mbbl of oil inventory ( December 31, 2015 - 616 Mbbl) NAR. In the six months ended June 30, 2016 , the Company recorded oil inventory impairment of $0.7 million ( six months ended June 30, 2015 - $ nil ) related to lower oil prices.

Convertible Senior Notes and De

Convertible Senior Notes and Debt Issuance Costs	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Convertible Senior Notes	Convertible Senior Notes and Debt Issuance Costs On April 6, 2016, the Company issued $100 million aggregate principal amount of Notes in a private placement to qualified institutional buyers. On April 22, 2016 , the Company issued an additional $15 million aggregate principal amount of the Notes pursuant to the underwriters’ exercise of their option to acquire additional Notes. The Notes bear interest at a rate of 5.00% per year, payable semi-annually in arrears on April 1 and October 1 of each year, beginning on October 1, 2016. The Notes will mature on April 1, 2021, unless earlier redeemed, repurchased or converted. The Notes are convertible at the option of the holder at any time prior to the close of business on the business day immediately preceding the maturity date. The conversion rate is initially 311.4295 shares of Common Stock per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $3.21 per share of Common Stock). The conversion rate is subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, the Company will increase the conversion rate for a holder who elects to convert its Notes in connection with such a corporate event in certain circumstances. The Company may not redeem the Notes prior to April 5, 2019, except in certain circumstances following a fundamental change (as defined in the indenture governing the Notes). The Company may redeem for cash all or any portion of the Notes, at its option, on or after April 5, 2019, if (terms below are as defined in the indenture governing the Notes): (i) the last reported sale price of the Company's Common Stock has been at least 150% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date on which the Company provides notice of redemption; and (ii) the Company has filed all reports that it is required to file with the SEC pursuant to Section 13 or 15(d) of the Exchange Act, as applicable (other than current reports on Form 8-K), during the twelve months preceding the date on which the Company provides such notice. The redemption price will be equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the Notes. If the Company undergoes a fundamental change, holders may require the Company to repurchase for cash all or any portion of their Notes at a fundamental change repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. Net proceeds from the sale of the Notes were $108.9 million , after deducting the initial purchasers' discount and the offering expenses payable by the Company. The Company intends to use the net proceeds from the sale of Notes for general corporate purposes, which may include acquisitions and/or capital expenditures. In connection with the issuance of the Notes, the Company incurred $6.1 million of debt issuance costs, which have been presented as a direct deduction against the carrying amount of the Notes. As of June 30, 2016 , the balance of unamortized debt issuance costs was $5.9 million . The Company also incurred debt issuance costs in connection with its credit facility which have been presented as other long-term assets and are being amortized to interest expense using the effective interest method over the term of the credit facility. The following table presents total interest expense recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Contractual interest and other financing expenses $ 1,712 $ — $ 2,091 $ — Amortization of debt issuance costs 489 — 629 — $ 2,201 $ — $ 2,720 $ — Credit Facility On June 2, 2016, the Company entered into a Second Amendment (the "Second Amendment") to its credit agreement dated September 18, 2015 (the "credit facility"). Pursuant to the Second Amendment, among other things, t he committed borrowing base under the Company's credit facility was reduced from $200 million to $185 million , with $160 million readily available and $25 million subject to the consent of all lenders. Further, the amount of permitted senior debt under the Company's credit facility was decreased from $600 million to $500 million .

Share Capital

Share Capital	6 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [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, one share is designated as Special A Voting Stock, par value $0.001 per share, and one share is designated as Special B Voting Stock, par value $0.001 per share. Shares of Common Stock Exchangeable Shares of Gran Tierra Exchangeco Inc. Exchangeable Shares of Gran Tierra Goldstrike Inc. Balance, December 31, 2015 273,442,799 4,933,177 3,638,889 Shares issued for acquisition (Note 3) 13,656,719 — — Options exercised 2,165,370 — — Exchange of exchangeable shares 58,000 (58,000 ) — Balance, June 30, 2016 289,322,888 4,875,177 3,638,889 Loss per Share Basic loss per share is calculated by dividing 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 income (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. Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Weighted average number of common and exchangeable shares outstanding 296,565,530 286,393,772 295,188,878 286,294,595 Weighted average shares issuable pursuant to stock options — — — — Weighted average shares assumed to be purchased from proceeds of stock options — — — — Weighted average number of diluted common and exchangeable shares outstanding 296,565,530 286,393,772 295,188,878 286,294,595 Stock options and shares issuable upon conversion of the Notes were excluded from the diluted loss per share calculation as the stock options and shares issuable upon conversion of the Notes were anti-dilutive. Equity Compensation Awards In December 2015, the Company's Board of Directors approved a new equity compensation program for 2016 to realign the Company's compensation programs with its renewed short and long-term strategy. The 2016 equity compensation program reflects the Company's emphasis on pay-for-performance. In prior years, all equity awards were subject to vesting conditions based solely on the recipient’s continued employment over a specified period of time. In contrast, 80% of the equity awards granted in early 2016 consisted of Performance Stock Units (“PSUs”) and 20% consisted of stock options. Gran Tierra's Compensation Committee and Board of Directors believed it was important to revise the Company's long-term incentive program to incorporate a new form of equity award that vests based on the achievement of certain key measures of performance. The purpose of this change was to align the Company's executives and employees to achieve the operational goals established by the Board of Directors, total shareholder return and increase the net asset value per share for stockholders. The Company’s equity compensation awards outstanding as of June 30, 2016 , include PSUs, deferred share units (“DSUs”), restricted stock units (“RSUs”) and stock options. The Company records stock-based compensation expense, measured at the fair value of the awards that are ultimately expected to vest, in the consolidated financial statements. Fair values are determined using pricing models such as the Black-Scholes-Merton or Monte Carlo simulation stock option-pricing models and/or observable share prices. For equity-settled stock-based compensation awards, fair values are determined at the grant date and are recognized over the requisite service period. For cash-settled stock-based compensation awards, fair values are determined at each reporting date and periodic changes are recognized as compensation costs, with a corresponding change to liabilities. Stock-based compensation expense is capitalized as part of oil and natural gas properties or expensed as part of operating expenses or G&A expenses, as appropriate. The following table provides information about PSU, DSU, RSU and stock option activity for the six months ended June 30, 2016 : PSUs DSUs RSUs Stock Options Number of Outstanding Share Units Number of Outstanding Share Units Number of Outstanding Share Units Number of Outstanding Stock Options Weighted Average Exercise Price/Stock Option ($) Balance, December 31, 2015 — — 1,015,457 12,851,557 4.60 Granted 2,297,700 117,621 — 1,302,350 2.65 Exercised — — (460,614 ) (2,165,370 ) 2.47 Forfeited — — (173,830 ) (1,563,903 ) (6.07 ) Expired — — — (1,517,500 ) (6.41 ) Balance, June 30, 2016 2,297,700 117,621 381,013 8,907,134 4.27 The amounts recognized for stock-based compensation were as follows: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Compensation costs for PSUs $ 707 $ — $ 871 $ — Compensation costs for stock options 813 1,109 1,784 687 Compensation costs for DSUs 404 — 550 — Compensation costs for RSUs 341 597 705 537 2,265 1,706 3,910 1,224 Less: Stock-based compensation costs capitalized (203 ) (80 ) (388 ) (111 ) Stock-based compensation expense $ 2,062 $ 1,626 $ 3,522 $ 1,113 Stock-based compensation expense for the three and six months ended June 30, 2016 and 2015 , was primarily recorded in G&A expenses. At June 30, 2016 , there was $9.9 million ( December 31, 2015 - $3.9 million ) of unrecognized compensation cost related to unvested PSUs, stock options, DSUs and RSUs which is expected to be recognized over a weighted average period of 2.2 years. PSUs PSUs 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 units or a cash payment equal to the value of the underlying shares. PSUs will cliff vest after three years, subject to the continued employment of the grantee. The number of PSUs that vest may range from zero to 200% of the target number granted based on the Company’s performance with respect to the applicable performance targets. The performance targets for the PSUs outstanding as of June 30, 2016 , are as follows: (i) 50% of the award is subject to targets relating to the total shareholder return (“TSR”) of the Company against a group of peer companies; (ii) 25% of the award is subject to targets relating to net asset value ("NAV") of the Company per share and NAV is based on before tax net present value discounted at 10% of proved plus probable reserves; and (iii) 25% of the award is subject to targets relating to the execution of corporate strategy. The compensation cost of PSUs is subject to adjustment based upon the attainability of these performance targets. No settlement will occur with respect to the portion of the PSU award subject to each performance target for results below the applicable minimum threshold for that target. PSUs in excess of the target number granted will vest and be settled if performance exceeds the targeted performance goals. The Company currently intends to settle PSUs in cash. DSUs and RSUs DSUs and RSUs entitle the holder to receive, either the underlying number of shares of the Company's Common Stock upon vesting of such units or, at the option of the Company, a cash payment equal to the value of the underlying shares. The Company's historic practice has been to settle RSUs in cash and the Company currently intends to settle the RSUs and DSUs outstanding as of June 30, 2016 in cash. Once a DSU or RSU is vested, it is immediately settled. During the six months ended June 30, 2016 , DSUs were granted to directors and will vest 100% at such time the grantee ceases to be a member of the Board of Directors. Stock Options Each stock option permits the holder to purchase one share of Common Stock at the stated exercise price. The exercise price equals the market price of a share of Common Stock at the time of grant. Stock options generally vest over three years. The term of stock options granted starting in May of 2013 is five years or three months after the grantee’s end of service to the Company, whichever occurs first. Stock options granted prior to May of 2013 continue to have a term of ten years or three months after the end of the grantee’s service to the Company, whichever occurs first. For the six months ended June 30, 2016 , 2,165,370 shares of Common Stock were issued for cash proceeds of $5.4 million ( six months ended June 30, 2015 - $0.6 million ) upon the exercise of stock options. The weighted average grant date fair value for stock options granted in three months ended June 30, 2016 , was $1.06 ( three months ended June 30, 2015 - $1.43 ) and for the six months ended June 30, 2016 , was $1.12 ( six months ended June 30, 2015 - $1.28 ).

Asset Retirement Obligation

Asset Retirement Obligation	6 Months Ended
	Jun. 30, 2016
Asset Retirement Obligation Disclosure [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: Six Months Ended Year Ended (Thousands of U.S. Dollars) June 30, 2016 December 31, 2015 Balance, beginning of period $ 33,224 $ 35,812 Settlements (681 ) (6,317 ) Liability incurred 1,208 1,556 Liabilities assumed in acquisition (Note 3) 11,852 — Accretion 1,273 1,313 Revisions in estimated liability (3,036 ) 860 Balance, end of period $ 43,840 $ 33,224 Asset retirement obligation - current $ 2,970 $ 2,146 Asset retirement obligation - long-term 40,870 31,078 $ 43,840 $ 33,224 For the six months ended June 30, 2016 , settlements included cash payments of $0.5 million with the balance in accounts payable and accrued liabilities at June 30, 2016 . Revisions to 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. At June 30, 2016 , the fair value of assets that are legally restricted for purposes of settling the asset retirement obligation was $8.9 million ( December 31, 2015 - $2.9 million ). These assets are accounted for as restricted cash on the Company's interim unaudited condensed consolidated balance sheets.

Taxes

Taxes	6 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Taxes	Taxes The Company's effective tax rate was 31% in the six months ended June 30, 2016 , compared with (1)% in the corresponding period in 2015 . The Company's effective tax rate differed from the U.S. statutory rate of 35% primarily due to an increase in the valuation allowance, which was largely attributable to impairment losses in Brazil, as well as non-deductible local taxes, stock based compensation and a third party royalty in Colombia. These items were partially offset by the impact of foreign taxes, foreign currency translation adjustments and other permanent differences, which mainly relates to non-taxable gain arising on the acquisition of Petroamerica and uncertain tax position adjustments, partially offset by prior periods true-up adjustments and other non-deductible expenses. The deferred tax recovery for six months ended June 30, 2016 , included $53.1 million associated with the ceiling test impairment loss in Colombia. 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 amounts of $3.1 million and $3.8 million , respectively, for the equity tax expense in the consolidated statement of operations during the six months ended June 30, 2016 and 2015 . At June 30, 2016 , accounts payable included $1.6 million (December 31, 2015 - $ nil ) which will be paid in September 2016 .

Credit Facility

Credit Facility	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Credit Facility	Convertible Senior Notes and Debt Issuance Costs On April 6, 2016, the Company issued $100 million aggregate principal amount of Notes in a private placement to qualified institutional buyers. On April 22, 2016 , the Company issued an additional $15 million aggregate principal amount of the Notes pursuant to the underwriters’ exercise of their option to acquire additional Notes. The Notes bear interest at a rate of 5.00% per year, payable semi-annually in arrears on April 1 and October 1 of each year, beginning on October 1, 2016. The Notes will mature on April 1, 2021, unless earlier redeemed, repurchased or converted. The Notes are convertible at the option of the holder at any time prior to the close of business on the business day immediately preceding the maturity date. The conversion rate is initially 311.4295 shares of Common Stock per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $3.21 per share of Common Stock). The conversion rate is subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, the Company will increase the conversion rate for a holder who elects to convert its Notes in connection with such a corporate event in certain circumstances. The Company may not redeem the Notes prior to April 5, 2019, except in certain circumstances following a fundamental change (as defined in the indenture governing the Notes). The Company may redeem for cash all or any portion of the Notes, at its option, on or after April 5, 2019, if (terms below are as defined in the indenture governing the Notes): (i) the last reported sale price of the Company's Common Stock has been at least 150% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date on which the Company provides notice of redemption; and (ii) the Company has filed all reports that it is required to file with the SEC pursuant to Section 13 or 15(d) of the Exchange Act, as applicable (other than current reports on Form 8-K), during the twelve months preceding the date on which the Company provides such notice. The redemption price will be equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the Notes. If the Company undergoes a fundamental change, holders may require the Company to repurchase for cash all or any portion of their Notes at a fundamental change repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. Net proceeds from the sale of the Notes were $108.9 million , after deducting the initial purchasers' discount and the offering expenses payable by the Company. The Company intends to use the net proceeds from the sale of Notes for general corporate purposes, which may include acquisitions and/or capital expenditures. In connection with the issuance of the Notes, the Company incurred $6.1 million of debt issuance costs, which have been presented as a direct deduction against the carrying amount of the Notes. As of June 30, 2016 , the balance of unamortized debt issuance costs was $5.9 million . The Company also incurred debt issuance costs in connection with its credit facility which have been presented as other long-term assets and are being amortized to interest expense using the effective interest method over the term of the credit facility. The following table presents total interest expense recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Contractual interest and other financing expenses $ 1,712 $ — $ 2,091 $ — Amortization of debt issuance costs 489 — 629 — $ 2,201 $ — $ 2,720 $ — Credit Facility On June 2, 2016, the Company entered into a Second Amendment (the "Second Amendment") to its credit agreement dated September 18, 2015 (the "credit facility"). Pursuant to the Second Amendment, among other things, t he committed borrowing base under the Company's credit facility was reduced from $200 million to $185 million , with $160 million readily available and $25 million subject to the consent of all lenders. Further, the amount of permitted senior debt under the Company's credit facility was decreased from $600 million to $500 million .

Contingencies

Contingencies	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies On June 6, 2016, the Company received a positive decision from the Chamber of Commerce of Bogotá Center for Arbitration and Conciliation tribunal (the "Tribunal") relating to its dispute with the Agencia Nacional de Hidrocarburos (National Hydrocarbons Agency) of Colombia ("ANH") with respect to whether all production from the Moqueta Exploitation Area of the Chaza Block exploration and production contract ("Chaza Contract") was subject to an additional royalty (the "HPR Royalty"). In its decision, the Tribunal found that the HPR Royalty under the Chaza Contract was only payable when the accumulated oil production from the Moqueta Exploitation Area exceeded 5.0 MMbbl . That production threshold was reached on April 30, 2015, and since that time the Company has been paying the HPR Royalty on production from the Moqueta Exploitation Area. The ANH and Gran Tierra are engaged in ongoing discussions regarding the interpretation of whether certain transportation and related costs are eligible to be deducted in the calculation of the HPR royalty. 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 $45.2 million as at June 30, 2016 . At this time no amount has been accrued in the interim unaudited condensed consolidated financial statements as Gran Tierra does not consider it probable that a loss will be incurred. 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. In addition to the above, Gran Tierra has a number of 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. Letters of credit At June 30, 2016 , the Company had provided promissory notes totaling $72.4 million ( December 31, 2015 - $76.5 million ) as security for letters of credit relating to work commitment guarantees contained in exploration contracts and other capital or operating requirements .

Financial Instruments, Fair Val

Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk	6 Months Ended
	Jun. 30, 2016
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 June 30, 2016 , the Company’s financial instruments recognized in the balance sheet consist of cash and cash equivalents, restricted cash, accounts receivable, trading securities, derivatives assets, accounts payable and accrued liabilities, Notes, PSU liability included in other long-term liabilities, and RSU liability included in accounts payable and accrued liabilities and other long-term liabilities. Fair Value Measurement The fair value of trading securities, derivative assets and RSU and PSU liabilities are being remeasured at the estimated fair value at the end of each reporting period. The fair value of trading securities which were received as consideration on the sale of the Company's Argentina business unit is estimated based on quoted market prices in an active market. The fair value of commodity price and foreign currency derivatives is estimated based on various factors, including quoted market prices in active markets and quotes from third parties. The Company also performs an internal valuation to ensure the reasonableness of third party quotes. In consideration of counterparty credit risk, the Company assessed the possibility of whether the counterparty to the derivative would default by failing to make any contractually required payments. Additionally, the Company considers that it is of substantial credit quality and has the financial resources and willingness to meet its potential repayment obligations associated with the derivative transactions. The fair value of the RSU liability was estimated based on quoted market prices in an active market. The fair value of the PSU liability was estimated based on quoted market prices in an active market and an option pricing model such as the Monte Carlo simulation option-pricing models. The fair value of trading securities, derivative assets, and RSU and PSU liabilities at June 30, 2016 , and December 31, 2015 , were as follows: (Thousands of U.S. Dollars) As at June 30, 2016 As at December 31, 2015 Trading securities $ 3,979 $ 6,250 Commodity price derivative asset 5,896 — Foreign currency derivative asset 1,118 — $ 10,993 $ 6,250 RSU and PSU liability $ 2,129 $ 1,189 The following table presents gains or losses on financial instruments recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Trading securities loss (gain) $ 1,380 $ (1,688 ) $ 2,225 $ (2,100 ) Commodity price derivative gain (1,334 ) — (1,334 ) — Foreign currency derivatives (gain) loss (1,118 ) 322 (1,118 ) 692 Financial instruments gain $ (1,072 ) $ (1,366 ) $ (227 ) $ (1,408 ) These gains and losses are presented as financial instruments gains or losses in the interim unaudited condensed consolidated statements of operations and cash flows. The fair value of long-term restricted cash approximates its carrying value because interest rates are variable and reflective of market rates. Financial instruments not recorded at fair value include the Notes (Note 6). At June 30, 2016 , the carrying amount of the Notes was $109.1 million , which represents the aggregate principal amount less unamortized debt issuance costs, and the fair value was $144.6 million . 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 June 30, 2016 , and December 31, 2015 , the fair value of the trading securities acquired in connection with the disposal of the Argentina business unit and the RSU liability was determined using Level 1 inputs. At June 30, 2016 , the fair value of the derivative assets was determined using Level 2 inputs. The fair value of the PSU liability was determined using Level 3 inputs. The disclosure in the paragraph above regarding the fair value of the Notes was determined using Level 2 inputs based on the indicative pricing published by certain investment banks or trading levels of the Notes, which are not listed on any securities exchange or quoted on an inter-dealer automated quotation system. The disclosure in the paragraph above regarding the fair value of cash and restricted cash was 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. Commodity Price Derivatives The Company utilizes commodity price derivatives to manage the variability in cash flows associated with the forecasted sale of its oil production, reduce commodity price risk and provide a base level of cash flow in order to assure it can execute at least a portion of its capital spending. At June 30, 2016 , the Company had outstanding commodity price derivative positions as follows: Period and type of instrument Volume, bopd Reference Sold Put Purchased Put Sold Call Collar: June 1, 2016 to May 31, 2017 10,000 ICE Brent $ 35 $ 45 $ 65 The Company paid a premium of $4.6 million , or $1.25 per bbl, upon entering into the commodity price derivative. Collars are a combination of put options (floor) and sold call options (ceiling). For a collar position, the counterparty is required to make a payment to the Company if the settlement price for any settlement period is below the floor strike price while the Company is required to make payment to the counterparty if the settlement price for any settlement period is above the ceiling strike price. Neither party is required to make a payment to the other party if the settlement price for any settlement period is equal to or greater than the floor strike price and equal to or less than the ceiling strike price. Foreign Currency Derivatives The Company utilizes foreign currency derivatives to manage the variability in cash flows associated with the Company's forecasted Colombian peso ("COP") denominated costs. At June 30, 2016 , the Company had outstanding foreign currency derivative positions as follows: Period and type of instrument Amount hedged (COP) Reference Purchased Call (COP) Sold Put (COP) Sold Put (COP) Collar: June 1, 2016 to June 30, 2016 9,794.6 COP 3,000 3,265 3,310 Collar: July 1, 2016 to September 30, 2016 25,064.6 COP 3,000 3,275 3,320 Collar: October 1, 2016 to December 31, 2016 20,930.0 COP 3,000 3,285 3,330 Collar: January 1, 2017 to March 31, 2017 31,597.6 COP 3,100 3,300 3,345 Collar: April 1, 2017 to May 31, 2017 22,697.2 COP 3,100 3,310 3,370 110,084.0 The Company's cash flow is only impacted when the actual settlements under the derivative contracts result in making or receiving a payment to or from the counterparty. These cash settlements represent the cumulative gains and losses on the Company's derivative instruments for the periods presented and do not include a recovery of costs that were paid to acquire or modify the derivative instruments that were settled. While the use of these derivative instruments may limit or partially reduce the downside risk of adverse commodity price and foreign exchange movements, their use also may limit future income and gains from favorable commodity price and foreign exchange movements.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	6 Months Ended
	Jun. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Net changes in assets and liabilities from operating activities were as follows: Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 Accounts receivable and other long-term assets $ (9,156 ) $ 23,652 Derivatives (4,562 ) — Inventory 4,365 (7,697 ) Prepaids 1,102 2,133 Accounts payable and accrued and other long-term liabilities (5,628 ) (20,319 ) Taxes receivable and payable 7,249 (44,273 ) Net changes in assets and liabilities from operating activities $ (6,630 ) $ (46,504 ) The following table provides additional supplemental cash flow disclosures: Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 Non-cash investing activities: Net liabilities related to property, plant and equipment, end of period $ 24,497 $ 33,658

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On June 30, 2016, Gran Tierra Energy International Holdings Ltd., a wholly-owned subsidiary of the Company, entered into a share purchase agreement (the "Acquisition Agreement") to acquire all of the issued and outstanding common shares of PetroLatina Energy Ltd. ("PetroLatina") for cash consideration of $525.0 million (the "Acquisition"), subject to customary working capital and other adjustments. Funding for the Acquisition will consist of an initial payment of $500.0 million at closing and a deferred payment of $25.0 million to be paid prior to December 31, 2016. Subsequent to the signing of the Acquisition Agreement, the Company paid $5.0 million , which funds are to be held in escrow and applied to the initial payment at closing. The Acquisition is also subject to customary closing conditions, including, among other things, any required regulatory approval. Approval from the ANH was received on July 29, 2016 and the Acquisition is expected to close prior to August 31, 2016. PetroLatina is a private, independent exploration and production company, incorporated in England and Wales, with assets primarily in the Middle Magdalena Basin of Colombia. Upon completion of the transaction, PetroLatina will become an indirect wholly-owned subsidiary of Gran Tierra. On July 8, 2016, the Company issued approximately 57.8 million subscription receipts (“Subscription Receipts”) in a private placement to eligible purchasers at a price of $3.00 per Subscription Receipt for gross proceeds of approximately $173.5 million . Each Subscription Receipt will entitle the holder to automatically receive one common share of the Company upon closing of the Acquisition upon the satisfaction of certain conditions. The gross proceeds from the sale of the Subscription Receipts will be held in escrow until the Acquisition close date and will be recorded as restricted cash by the Company. The Company expects to fund the Acquisition through a combination of the Company's current cash balance, gross proceeds of $173.5 million from the Subscription Receipts, available borrowings under the Company's existing revolving loan and $130.0 million of borrowings under a new term loan that is contingent upon the closing of the Acquisition. The Acquisition Agreement may be terminated by either Gran Tierra or the vendors under certain circumstances set forth in the Acquisition Agreement, including, among other circumstances, the failure of the Acquisition to be consummated on or before October 31, 2016. For further information regarding the Acquisition, please see “Risk Factors - The acquisition of PetroLatina may not be completed, and even if the acquisition is completed, we may fail to realize the benefits anticipated as a result of the acquisition.”

Significant Accounting Polici21

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Convertible senior notes	Convertible Senior Notes The Company accounts for its 5.00% Convertible Senior Notes due 2021 (the "Notes") as a liability in their entirety. The embedded features of the Notes were assessed for bifurcation from the Notes under the applicable provisions, including the basic conversion feature, the fundamental change make-whole provision and the put and call options. Based on an assessment, the Company concluded that these embedded features did not meet the criteria to be accounted for separately. The Company incurred debt issuance costs in connection with the issuance of the Notes which have been presented as a direct deduction against the carrying amount of the Notes and are being amortized to interest expense using the effective interest method over the contractual term of the Notes.
Derivatives	Derivatives The Company's commodity price and foreign currency derivatives are recorded on its interim unaudited condensed consolidated balance sheet at fair value as either an asset or a liability with changes in fair value recognized in the interim unaudited condensed consolidated statements of operations. While the Company utilizes derivative instruments to manage the price risk attributable to its expected oil production and foreign exchange risk, it has elected not to designate its derivative instruments as accounting hedges under the accounting guidance.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (the "FASB") issued guidance regarding the accounting for revenue from contracts with customers. In August 2015, the FASB issued Accounting Standards Update (“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. In March 2016, the FASB issued ASU 2016-08, “Principal versus Agent Considerations (Reporting Revenue Gross versus Net)" which clarifies implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU 2016-10, “Identifying Performance Obligations and Licensing" which clarifies implementation guidance. In May 2016, the FASB issued ASU 2016-12, “Narrow-Scope Improvements and Practical Expedients" which reduces the potential for diversity in practice at initial application and the cost and complexity of applying Topic 606 both at transition and on an ongoing basis. The Company is currently assessing the impact the new revenue recognition model will have on its consolidated financial position, results of operations, cash flows, and disclosure. Simplifying the Accounting for Measurement - Period Adjustments In September 2015, the FASB issued ASU 2015-16, "Simplifying the Accounting for Measurement - Period Adjustments". The amendments require that an acquirer recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which the adjustments are determined and eliminates the requirement to retrospectively revise prior periods. Additionally, an acquirer should record in the same period the effects on earnings of any changes in the provisional accounts, calculated as if the accounting had been completed at the acquisition date. The ASU was effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. 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. Leases In February 2016, the FASB issued ASU 2016-02, “Leases". This ASU will require most lease assets and lease liabilities to be recognized on the balance sheet and the disclosure of key information about lease arrangements. The ASU will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. The Company is currently assessing the impact the new lease standard will have on its consolidated financial position, results of operations, cash flows, and disclosure. Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting ". This ASU simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for forfeitures, income taxes, and statutory tax withholding requirements. The ASU will be effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The Company is currently assessing the impact this update will have on its consolidated financial position, results of operations, cash flows, and disclosure.

Business Combination (Tables)

Business Combination (Tables) - Petroamerica	6 Months Ended
	Jun. 30, 2016
Business Acquisition [Line Items]
Allocation of the Consideration Transferred Based on the Fair Values of Assets and Liabilities Acquired	The following table shows the allocation of the consideration transferred based on the fair values of the assets and liabilities acquired: (Thousands of U.S. Dollars) Consideration Transferred: Cash $ 70,625 Shares of Common Stock issued net of share issue costs 25,811 $ 96,436 Allocation of Consideration Transferred (1) : Oil and gas properties Proved $ 48,595 Unproved 50,054 Net working capital (including cash acquired of $19.7 million, restricted cash of $2.5 million and accounts receivable of $5.0 million) 24,202 Long-term restricted cash 8,167 Other long-term assets 1,570 Long-term deferred tax liability (10,105 ) Long-term portion of asset retirement obligation (11,556 ) Other long-term liabilities (2,779 ) Gain on acquisition (11,712 ) $ 96,436 (1) The allocation of the consideration transferred is incomplete and is subject to change. Management is continuing to review and assess information to accurately determine the acquisition date fair value of the assets and liabilities acquired. During the measurement period, Gran Tierra will continue to obtain information to assist in finalizing the fair value of net assets acquired, which may differ materially from the above preliminary estimates.
Pro Forma Results of Acquisition	Pro forma results for the six months ended June 30, 2016 and 2015, are shown below, as if the acquisition had occurred on January 1, 2015. Pro forma results are not indicative of actual results or future performance. Six Months Ended June 30, (Unaudited, thousands of U.S. Dollars, except per share amounts) 2016 2015 Oil and gas sales $ 129,587 $ 178,509 Net loss $ (120,317 ) $ (138,535 ) Net loss per share - basic and diluted $ (0.41 ) $ (0.48 )

Segment and Geographic Report23

Segment and Geographic Reporting (Tables)	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Reportable Geographic Segments	The following tables present information on the Company’s reportable segments and other activities: Three Months Ended June 30, 2016 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 69,271 $ — $ 2,442 $ — $ 71,713 Depletion, depreciation and accretion 30,458 71 1,024 331 31,884 Asset impairment 78,208 483 14,152 — 92,843 General and administrative expenses 4,430 387 241 2,917 7,975 Loss before income taxes (64,836 ) (744 ) (14,037 ) (6,779 ) (86,396 ) Segment capital expenditures 14,535 1,102 2,160 610 18,407 Three Months Ended June 30, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 67,627 $ — $ 1,723 $ — $ 69,350 Depletion, depreciation and accretion 37,061 147 1,575 405 39,188 Asset impairment — 5,285 25,000 — 30,285 General and administrative expenses 3,035 1,273 965 5,025 10,298 Income (loss) before income taxes 3,197 (8,261 ) (28,211 ) (4,488 ) (37,763 ) Segment capital expenditures 8,173 6,878 2,505 316 17,872 Six Months Ended June 30, 2016 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 125,571 $ — $ 3,545 $ — $ 129,116 Depletion, depreciation and accretion 66,194 212 1,742 648 68,796 Asset impairment 133,440 899 15,402 — 149,741 General and administrative expenses 7,695 796 533 7,237 16,261 Loss before income taxes (137,557 ) (1,456 ) (15,546 ) (1,982 ) (156,541 ) Segment capital expenditures (1) 36,522 2,369 4,880 816 44,587 Six Months Ended June 30, 2015 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Oil and natural gas sales $ 141,694 $ — $ 3,887 $ — $ 145,581 Depletion, depreciation and accretion 83,316 414 3,836 762 88,328 Asset impairment — 37,966 29,333 — 67,299 General and administrative expenses 5,751 2,313 1,592 7,936 17,592 Income (loss) before income taxes 6,125 (43,703 ) (35,092 ) (9,890 ) (82,560 ) Segment capital expenditures 29,295 44,577 16,411 1,035 91,318 (1) On January 13, 2016, the Company acquired all of the issued and outstanding common shares of Petroamerica, which acquisition was accounted for as a business combination (Note 3) and, therefore, property, plant and equipment acquired are not reflected in the table above. Additionally, on January 25, 2016, the Company acquired all of the issued and outstanding common shares of PetroGranada Colombia Limited ("PGC"), which acquisition was accounted for as an asset acquisition (Note 5) and property, plant and equipment acquired in this acquisition are not reflected in the table above.
Long-lived Assets by Geographical Area	As at June 30, 2016 (Thousands of U.S. Dollars) Colombia Peru Brazil All Other Total Property, plant and equipment $ 543,273 $ 96,433 $ 103,368 $ 4,189 $ 747,263 Goodwill 102,581 — — — 102,581 All other assets 146,191 16,404 3,211 146,769 312,575 Total Assets $ 792,045 $ 112,837 $ 106,579 $ 150,958 $ 1,162,419 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

Property, Plant and Equipment24

Property, Plant and Equipment and Inventory (Tables)	6 Months Ended
	Jun. 30, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, Plant and Equipment (Thousands of U.S. Dollars) As at June 30, 2016 As at December 31, 2015 Oil and natural gas properties Proved $ 2,111,268 $ 1,998,330 Unproved 366,079 310,771 2,477,347 2,309,101 Other 28,597 28,342 2,505,944 2,337,443 Accumulated depletion, depreciation and impairment (1,758,681 ) (1,548,450 ) $ 747,263 $ 788,993
Asset Impairment	Asset impairment for the three and six months ended June 30, 2016 , and 2015 was as follows: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Impairment of oil and gas properties $ 92,843 $ 30,285 $ 149,077 $ 67,299 Impairment of inventory — — 664 — $ 92,843 $ 30,285 $ 149,741 $ 67,299
Allocation of the Cost of the Acquisition Based on the Relative Fair Values of the Assets and Liabilities Acquired	The following table shows the allocation of the cost of the acquisition based on the relative fair values of the assets and liabilities acquired: (Thousands of U.S. Dollars) Cost of asset acquisition: Cash $ 37,727 Allocation of Consideration Transferred: Oil and gas properties Proved $ 12,228 Unproved 15,563 27,791 Net working capital (including cash acquired of $0.2 million and restricted cash of $18.6 million) 18,339 Long-term deferred tax liability (8,403 ) $ 37,727

Convertible Senior Notes and 25

Convertible Senior Notes and Debt Issuance Costs (Tables)	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Interest Expense Recognized	The following table presents total interest expense recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Contractual interest and other financing expenses $ 1,712 $ — $ 2,091 $ — Amortization of debt issuance costs 489 — 629 — $ 2,201 $ — $ 2,720 $ —

Share Capital (Tables)

Share Capital (Tables)	6 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [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, 2015 273,442,799 4,933,177 3,638,889 Shares issued for acquisition (Note 3) 13,656,719 — — Options exercised 2,165,370 — — Exchange of exchangeable shares 58,000 (58,000 ) — Balance, June 30, 2016 289,322,888 4,875,177 3,638,889
Weighted Average Share Outstanding	Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Weighted average number of common and exchangeable shares outstanding 296,565,530 286,393,772 295,188,878 286,294,595 Weighted average shares issuable pursuant to stock options — — — — Weighted average shares assumed to be purchased from proceeds of stock options — — — — Weighted average number of diluted common and exchangeable shares outstanding 296,565,530 286,393,772 295,188,878 286,294,595
PSU, DSU, RSU and Stock Option Activity	The following table provides information about PSU, DSU, RSU and stock option activity for the six months ended June 30, 2016 : PSUs DSUs RSUs Stock Options Number of Outstanding Share Units Number of Outstanding Share Units Number of Outstanding Share Units Number of Outstanding Stock Options Weighted Average Exercise Price/Stock Option ($) Balance, December 31, 2015 — — 1,015,457 12,851,557 4.60 Granted 2,297,700 117,621 — 1,302,350 2.65 Exercised — — (460,614 ) (2,165,370 ) 2.47 Forfeited — — (173,830 ) (1,563,903 ) (6.07 ) Expired — — — (1,517,500 ) (6.41 ) Balance, June 30, 2016 2,297,700 117,621 381,013 8,907,134 4.27
Amounts Recognized for Stock-based Compensation	The amounts recognized for stock-based compensation were as follows: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Compensation costs for PSUs $ 707 $ — $ 871 $ — Compensation costs for stock options 813 1,109 1,784 687 Compensation costs for DSUs 404 — 550 — Compensation costs for RSUs 341 597 705 537 2,265 1,706 3,910 1,224 Less: Stock-based compensation costs capitalized (203 ) (80 ) (388 ) (111 ) Stock-based compensation expense $ 2,062 $ 1,626 $ 3,522 $ 1,113

Asset Retirement Obligation (Ta

Asset Retirement Obligation (Tables)	6 Months Ended
	Jun. 30, 2016
Asset Retirement Obligation Disclosure [Abstract]
Changes in 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: Six Months Ended Year Ended (Thousands of U.S. Dollars) June 30, 2016 December 31, 2015 Balance, beginning of period $ 33,224 $ 35,812 Settlements (681 ) (6,317 ) Liability incurred 1,208 1,556 Liabilities assumed in acquisition (Note 3) 11,852 — Accretion 1,273 1,313 Revisions in estimated liability (3,036 ) 860 Balance, end of period $ 43,840 $ 33,224 Asset retirement obligation - current $ 2,970 $ 2,146 Asset retirement obligation - long-term 40,870 31,078 $ 43,840 $ 33,224

Financial Instruments, Fair V28

Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value of Trading Securities and Contingent Consideration	The fair value of trading securities, derivative assets, and RSU and PSU liabilities at June 30, 2016 , and December 31, 2015 , were as follows: (Thousands of U.S. Dollars) As at June 30, 2016 As at December 31, 2015 Trading securities $ 3,979 $ 6,250 Commodity price derivative asset 5,896 — Foreign currency derivative asset 1,118 — $ 10,993 $ 6,250 RSU and PSU liability $ 2,129 $ 1,189
Gains or Losses on Financial Instruments	The following table presents gains or losses on financial instruments recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended June 30, Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 2016 2015 Trading securities loss (gain) $ 1,380 $ (1,688 ) $ 2,225 $ (2,100 ) Commodity price derivative gain (1,334 ) — (1,334 ) — Foreign currency derivatives (gain) loss (1,118 ) 322 (1,118 ) 692 Financial instruments gain $ (1,072 ) $ (1,366 ) $ (227 ) $ (1,408 )
Schedule of Commodity Price Derivative Positions	At June 30, 2016 , the Company had outstanding commodity price derivative positions as follows: Period and type of instrument Volume, bopd Reference Sold Put Purchased Put Sold Call Collar: June 1, 2016 to May 31, 2017 10,000 ICE Brent $ 35 $ 45 $ 65
Schedule of Foreign Currency Derivative Positions	At June 30, 2016 , the Company had outstanding foreign currency derivative positions as follows: Period and type of instrument Amount hedged (COP) Reference Purchased Call (COP) Sold Put (COP) Sold Put (COP) Collar: June 1, 2016 to June 30, 2016 9,794.6 COP 3,000 3,265 3,310 Collar: July 1, 2016 to September 30, 2016 25,064.6 COP 3,000 3,275 3,320 Collar: October 1, 2016 to December 31, 2016 20,930.0 COP 3,000 3,285 3,330 Collar: January 1, 2017 to March 31, 2017 31,597.6 COP 3,100 3,300 3,345 Collar: April 1, 2017 to May 31, 2017 22,697.2 COP 3,100 3,310 3,370 110,084.0

Supplemental Cash Flow Inform29

Supplemental Cash Flow Information (Tables)	6 Months Ended
	Jun. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Net Changes in Assets and Liabilities from Operating Activities	Net changes in assets and liabilities from operating activities were as follows: Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 Accounts receivable and other long-term assets $ (9,156 ) $ 23,652 Derivatives (4,562 ) — Inventory 4,365 (7,697 ) Prepaids 1,102 2,133 Accounts payable and accrued and other long-term liabilities (5,628 ) (20,319 ) Taxes receivable and payable 7,249 (44,273 ) Net changes in assets and liabilities from operating activities $ (6,630 ) $ (46,504 )
Additional Supplemental Cash Flow Disclosures	The following table provides additional supplemental cash flow disclosures: Six Months Ended June 30, (Thousands of U.S. Dollars) 2016 2015 Non-cash investing activities: Net liabilities related to property, plant and equipment, end of period $ 24,497 $ 33,658

Significant Accounting Polici30

Significant Accounting Policies (Details)	Jun. 30, 2016
5.00% Convertible Senior Notes due 2021 | Convertible debt
Debt Instrument [Line Items]
Interest rate on convertible senior notes	5.00%

Business Combination - Addition

Business Combination - Additional Information (Details) $ / shares in Units, $ in Thousands	Jan. 13, 2016USD ($)shares	Jun. 30, 2016USD ($)$ / shares	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)$ / sharesshares	Jun. 30, 2015USD ($)	Jan. 13, 2016CAD / shares	Jan. 13, 2016USD ($)$ / shares	Dec. 31, 2015$ / shares
Business Acquisition [Line Items]
Common shares, par value (in dollars per share) | $ / shares		$ 0.001		$ 0.001				$ 0.001
Gain on acquisition		$ 0	$ 0	$ 11,712	$ 0
Oil and natural gas sales		71,713	69,350	129,116	145,581
Loss after tax		63,559	$ 38,564	$ 108,591	$ 83,430
Common Stock
Business Acquisition [Line Items]
Consideration transferred for acquisition, number of shares issued | shares				13,656,719
Petroamerica
Business Acquisition [Line Items]
Cash paid for each share held (in Canadian dollars per share) | CAD / shares						CAD 1.33
Consideration payable in cash (up to, as a percent)							70.00%
Cash consideration	$ 70,625
Fair value of shares issued in acquisition							$ 25,800
Net purchase price	72,200
Net working capital							$ 24,202
Gain on acquisition	$ 11,712			$ 11,700
Petroamerica | Subsidiaries
Business Acquisition [Line Items]
Oil and natural gas sales				8,900
Loss after tax				18,200
Petroamerica | General and Administrative Expense
Business Acquisition [Line Items]
Acquisition costs		$ 1,300		$ 1,300
Petroamerica | Common Stock
Business Acquisition [Line Items]
Shares of Gran Tierra per share of Petroamerica							0.40
Consideration transferred for acquisition, number of shares issued | shares	13,700,000
Common shares, par value (in dollars per share) | $ / shares							$ 0.001

Business Combination - Allocati

Business Combination - Allocation of the Consideration Transferred Based on the Fair Values of Assets and Liabilities Acquired (Details) - USD ($) $ in Thousands	Jan. 13, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Oil and gas properties
Gain on acquisition		$ 0	$ 0	$ (11,712)	$ 0
Petroamerica
Consideration Transferred:
Cash	$ 70,625
Shares of Common Stock issued net of share issue costs	25,811
Consideration transferred	96,436
Oil and gas properties
Proved	48,595
Unproved	50,054
Net working capital (including cash acquired of $19.7 million, restricted cash of $2.5 million and accounts receivable of $5.0 million)	24,202
Long-term restricted cash	8,167
Other long-term assets	1,570
Long-term deferred tax liability	(10,105)
Long-term portion of asset retirement obligation	(11,556)
Other long-term liabilities	(2,779)
Gain on acquisition	(11,712)			$ (11,700)
Total consideration transferred	96,436
Cash acquired	19,700
Restricted cash acquired	2,500
Accounts receivable acquired	$ 5,000

Business Combination - Pro Form

Business Combination - Pro Forma Results of Acquisition (Details) - Petroamerica - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Business Acquisition [Line Items]
Oil and gas sales	$ 129,587	$ 178,509
Net loss	$ (120,317)	$ (138,535)
Net loss per share - basic and diluted (in dollars per share)	$ (0.41)	$ (0.48)

Segment and Geographic Report34

Segment and Geographic Reporting - Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Oil and natural gas sales	$ 71,713	$ 69,350	$ 129,116	$ 145,581
Depletion, depreciation and accretion	31,884	39,188	68,796	88,328
Asset impairment	92,843	30,285	149,741	67,299
General and administrative expenses	7,975	10,298	16,261	17,592
Income (loss) before income taxes	(86,396)	(37,763)	(156,541)	(82,560)
Segment capital expenditures	18,407	17,872	44,587	91,318
Colombia
Segment Reporting Information [Line Items]
Asset impairment	78,200		132,800
Brazil
Segment Reporting Information [Line Items]
Asset impairment	14,200	25,000	15,400	29,300
Operating Segments | Colombia
Segment Reporting Information [Line Items]
Oil and natural gas sales	69,271	67,627	125,571	141,694
Depletion, depreciation and accretion	30,458	37,061	66,194	83,316
Asset impairment	78,208	0	133,440	0
General and administrative expenses	4,430	3,035	7,695	5,751
Income (loss) before income taxes	(64,836)	3,197	(137,557)	6,125
Segment capital expenditures	14,535	8,173	36,522	29,295
Operating Segments | Peru
Segment Reporting Information [Line Items]
Oil and natural gas sales	0	0	0	0
Depletion, depreciation and accretion	71	147	212	414
Asset impairment	483	5,285	899	37,966
General and administrative expenses	387	1,273	796	2,313
Income (loss) before income taxes	(744)	(8,261)	(1,456)	(43,703)
Segment capital expenditures	1,102	6,878	2,369	44,577
Operating Segments | Brazil
Segment Reporting Information [Line Items]
Oil and natural gas sales	2,442	1,723	3,545	3,887
Depletion, depreciation and accretion	1,024	1,575	1,742	3,836
Asset impairment	14,152	25,000	15,402	29,333
General and administrative expenses	241	965	533	1,592
Income (loss) before income taxes	(14,037)	(28,211)	(15,546)	(35,092)
Segment capital expenditures	2,160	2,505	4,880	16,411
All Other
Segment Reporting Information [Line Items]
Oil and natural gas sales	0	0	0	0
Depletion, depreciation and accretion	331	405	648	762
Asset impairment	0	0	0	0
General and administrative expenses	2,917	5,025	7,237	7,936
Income (loss) before income taxes	(6,779)	(4,488)	(1,982)	(9,890)
Segment capital expenditures	$ 610	$ 316	$ 816	$ 1,035

Segment and Geographic Report35

Segment and Geographic Reporting - Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Property, plant and equipment	$ 747,263	$ 788,993
Goodwill	102,581	102,581
Total Assets	1,162,419	1,146,118
Continuing Operations
Segment Reporting Information [Line Items]
Property, plant and equipment	747,263	788,993
Goodwill	102,581	102,581
All other assets	312,575	254,544
Total Assets	1,162,419	1,146,118
Continuing Operations | Operating Segments | Colombia
Segment Reporting Information [Line Items]
Property, plant and equipment	543,273	574,351
Goodwill	102,581	102,581
All other assets	146,191	93,479
Total Assets	792,045	770,411
Continuing Operations | Operating Segments | Peru
Segment Reporting Information [Line Items]
Property, plant and equipment	96,433	95,069
Goodwill	0	0
All other assets	16,404	21,111
Total Assets	112,837	116,180
Continuing Operations | Operating Segments | Brazil
Segment Reporting Information [Line Items]
Property, plant and equipment	103,368	115,552
Goodwill	0	0
All other assets	3,211	2,236
Total Assets	106,579	117,788
Continuing Operations | All Other
Segment Reporting Information [Line Items]
Property, plant and equipment	4,189	4,021
Goodwill	0	0
All other assets	146,769	137,718
Total Assets	$ 150,958	$ 141,739

Property, Plant and Equipment36

Property, Plant and Equipment and Inventory - Schedule of Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Oil and natural gas properties	$ 2,505,944	$ 2,337,443
Accumulated depletion, depreciation and impairment	(1,758,681)	(1,548,450)
Total Property, Plant and Equipment (Notes 4 and 5)	747,263	788,993
Proved
Property, Plant and Equipment [Line Items]
Oil and natural gas properties	2,111,268	1,998,330
Unproved
Property, Plant and Equipment [Line Items]
Oil and natural gas properties	366,079	310,771
Oil and natural gas properties
Property, Plant and Equipment [Line Items]
Oil and natural gas properties	2,477,347	2,309,101
Other
Property, Plant and Equipment [Line Items]
Oil and natural gas properties	$ 28,597	$ 28,342

Property, Plant and Equipment37

Property, Plant and Equipment and Inventory - Additional Information (Details) $ in Thousands	Jan. 25, 2016USD ($)bbl	Jun. 30, 2016USD ($)bbl	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)bbl	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)bbl
Property, Plant and Equipment [Line Items]
Asset impairment		$ 92,843	$ 30,285	$ 149,741	$ 67,299
Net purchase price				19,388	0
Crude oil inventories		8,000		8,000		$ 17,800
Supplies		$ 1,300		$ 1,300		$ 1,300
Oil inventory (barrels) | bbl		244,000		244,000		616,000
Impairment of oil inventory		$ 0	0	$ 664	0
PGC
Property, Plant and Equipment [Line Items]
Net purchase price	$ 19,400
Net working capital	18,339
Contingent consideration	$ 4,000
Threshold by which contingent consideration is due (barrels) | bbl	8,000,000
Oil and natural gas properties | Assets | Income Approach Valuation Technique
Property, Plant and Equipment [Line Items]
Discount rate (percent)				10.00%
Colombia
Property, Plant and Equipment [Line Items]
Asset impairment		78,200		$ 132,800
Brazil
Property, Plant and Equipment [Line Items]
Asset impairment		14,200	25,000	15,400	29,300
Peru | Block 95
Property, Plant and Equipment [Line Items]
Asset impairment		$ 500	$ 5,300	$ 900	$ 38,000

Property, Plant and Equipment38

Property, Plant and Equipment and Inventory - Asset Impairment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Property, Plant and Equipment [Abstract]
Impairment of oil and gas properties	$ 92,843	$ 30,285	$ 149,077	$ 67,299
Impairment of inventory	0	0	664	0
Total asset impairment	$ 92,843	$ 30,285	$ 149,741	$ 67,299

Property, Plant and Equipment39

Property, Plant and Equipment and Inventory - Allocation of the Cost of the PetroGranada Colombia Limited Acquisition (Details) $ in Thousands	Jan. 25, 2016USD ($)
Oil and gas properties
Cash acquired	$ 200
Restricted cash acquired	18,600
PGC
Property, Plant and Equipment [Line Items]
Cash	37,727
Oil and gas properties
Proved	12,228
Unproved	15,563
Oil and gas properties	27,791
Net working capital (including cash acquired of $0.2 million and restricted cash of $18.6 million)	18,339
Long-term deferred tax liability	(8,403)
Cost of asset acquisition	$ 37,727

Convertible Senior Notes and 40

Convertible Senior Notes and Debt Issuance Costs - Narrative (Details) - Convertible debt - 5.00% Convertible Senior Notes due 2021	Apr. 06, 2016USD ($)day$ / shares	Apr. 22, 2016USD ($)	Jun. 30, 2016USD ($)
Debt Instrument [Line Items]
Aggregate principal amount of Convertible Senior Notes	$ 100,000,000	$ 15,000,000
Interest rate (as a percent)			5.00%
Conversion rate (as a percent)	0.3114295
Initial conversion price (in dollars per share) | $ / shares	$ 3.21
Threshold percentage of stock price trigger	150.00%
Threshold trading days | day	20
Threshold consecutive trading days	30 days
Redemption price percentage	100.00%
Repurchase percentage	100.00%
Net proceeds from sale of Notes		108,900,000
Debt issuance costs		$ 6,100,000
Unamortized debt issuance costs			$ 5,900,000

Convertible Senior Notes and 41

Convertible Senior Notes and Debt Issuance Costs - Interest Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Debt Instrument [Line Items]
Amortization of debt issuance costs			$ 629	$ 0
Total interest expense recognized	$ 2,201	$ 0	2,720	0
Convertible debt
Debt Instrument [Line Items]
Contractual interest and other financing expenses	1,712	0	2,091	0
Amortization of debt issuance costs	489	0	629	0
Total interest expense recognized	$ 2,201	$ 0	$ 2,720	$ 0

Share Capital - Additional Info

Share Capital - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 30, 2013	May 31, 2013	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized share capital (in shares)			595,000,002		595,000,002
Common stock, shares authorized			570,000,000		570,000,000
Common shares, par value (in dollars per share)			$ 0.001		$ 0.001		$ 0.001
Unrecognized compensation cost related to unvested stock options			$ 9,900		$ 9,900		$ 3,900
Unvested stock options recognition period					2 years 2 months 12 days
Options exercised (in shares)					2,165,370
Proceeds from issuance of shares of Common Stock (Note 7)					$ 5,350	$ 602
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted in period (as a percent)					20.00%
Vesting period					3 years
Term of stock options during employment		5 years
Term of stock options end of grantee's service		3 months
Term of stock options, expiration period	10 years
Weighted average grant date fair value for options granted (in dollars per option)			$ 1.06	$ 1.43	$ 1.12	$ 1.28
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted in period (as a percent)					80.00%
Vesting period					3 years
Award vesting percentage subject to targets relating to total shareholder return					50.00%
Award vesting percentage subject to targets relating to net asset value					25.00%
Net present value, discount rate					10.00%
Award vesting percentage subject to targets relating to the execution of corporate strategy					25.00%
PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					0.00%
PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					200.00%
DSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					100.00%
Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized			25,000,000		25,000,000
Preferred stock, par value (in dollars per share)			$ 0.001		$ 0.001
Special A Voting Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized			1		1
Preferred stock, par value (in dollars per share)			$ 0.001		$ 0.001
Special B Voting Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized			1		1
Preferred stock, par value (in dollars per share)			$ 0.001		$ 0.001

Share Capital - Schedule of Com

Share Capital - Schedule of Common Stock (Details)	6 Months Ended
	Jun. 30, 2016shares
Increase (Decrease) in Common Stock
Beginning balance (in shares)	273,442,799
Options exercised (in shares)	2,165,370
Ending balance (in shares)	289,322,888
Common Stock
Increase (Decrease) in Common Stock
Beginning balance (in shares)	273,442,799
Shares issued for acquisition (Note 3) (in shares)	13,656,719
Options exercised (in shares)	2,165,370
Exchange of exchangeable shares (in shares)	58,000
Ending balance (in shares)	289,322,888
Common Stock | Exchangeable Shares of Gran Tierra Exchangeco Inc.
Increase (Decrease) in Common Stock
Beginning balance (in shares)	4,933,177
Shares issued for acquisition (Note 3) (in shares)	0
Options exercised (in shares)	0
Exchange of exchangeable shares (in shares)	(58,000)
Ending balance (in shares)	4,875,177
Common Stock | Exchangeable Shares of Gran Tierra Goldstrike Inc.
Increase (Decrease) in Common Stock
Beginning balance (in shares)	3,638,889
Shares issued for acquisition (Note 3) (in shares)	0
Options exercised (in shares)	0
Exchange of exchangeable shares (in shares)	0
Ending balance (in shares)	3,638,889

Share Capital - Weighted Averag

Share Capital - Weighted Average Shares Outstanding (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average number of common and exchangeable shares outstanding	296,565,530	286,393,772	295,188,878	286,294,595
Weighted average shares issuable pursuant to stock options	0	0	0	0
Weighted average shares assumed to be purchased from proceeds of stock options	0	0	0	0
Weighted average number of diluted common and exchangeable shares outstanding	296,565,530	286,393,772	295,188,878	286,294,595

Share Capital - PSU, DSU, RSU a

Share Capital - PSU, DSU, RSU and Stock Option Activity (Details)	6 Months Ended
	Jun. 30, 2016$ / sharesshares
Number of Outstanding Stock Options
Beginning Balance (in shares)	12,851,557
Granted (in shares)	1,302,350
Exercised (in shares)	(2,165,370)
Forfeited (in shares)	(1,563,903)
Expired (in shares)	(1,517,500)
Ending Balance (in shares)	8,907,134
Weighted Average Exercise Price/Stock Option ($)
Beginning balance (in dollars per share) | $ / shares	$ 4.60
Granted (in dollars per share) | $ / shares	2.65
Exercised (in dollars per share) | $ / shares	2.47
Forfeited (in dollars per share) | $ / shares	(6.07)
Expired (in dollars per share) | $ / shares	(6.41)
Ending balance (in dollars per share) | $ / shares	$ 4.27
PSUs
Number of Outstanding Share Units
Beginning Balance (in shares)	0
Granted (in shares)	2,297,700
Exercised (in shares)	0
Forfeited (in shares)	0
Expired (in shares)	0
Ending Balance (in shares)	2,297,700
DSUs
Number of Outstanding Share Units
Beginning Balance (in shares)	0
Granted (in shares)	117,621
Exercised (in shares)	0
Forfeited (in shares)	0
Expired (in shares)	0
Ending Balance (in shares)	117,621
RSUs
Number of Outstanding Share Units
Beginning Balance (in shares)	1,015,457
Granted (in shares)	0
Exercised (in shares)	(460,614)
Forfeited (in shares)	(173,830)
Expired (in shares)	0
Ending Balance (in shares)	381,013

Share Capital - Amounts Recogni

Share Capital - Amounts Recognized for Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs	$ 2,265	$ 1,706	$ 3,910	$ 1,224
Less: Stock-based compensation costs capitalized	(203)	(80)	(388)	(111)
Stock-based compensation expense	2,062	1,626	3,522	1,113
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs	707	0	871	0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs	813	1,109	1,784	687
DSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs	404	0	550	0
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs	$ 341	$ 597	$ 705	$ 537

Asset Retirement Obligation - C

Asset Retirement Obligation - Changes in Asset Retirement Obligation (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2016	Dec. 31, 2015
Asset Retirement Obligation, Roll Forward Analysis
Beginning Balance	$ 33,224	$ 35,812
Settlements	(681)	(6,317)
Liability incurred	1,208	1,556
Liabilities assumed in acquisition (Note 3)	11,852	0
Accretion	1,273	1,313
Revisions in estimated liability	(3,036)	860
Balance, end of period	43,840	33,224
Asset retirement obligation - current			$ 2,970	$ 2,146
Asset retirement obligation - long-term			40,870	31,078
Asset retirement obligation	$ 33,224	$ 35,812	$ 43,840	$ 33,224

Asset Retirement Obligation - N

Asset Retirement Obligation - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Cash payments included in settlement	$ 464	$ 1,964
Fair value of legally restricted assets	$ 8,900		$ 2,900

Taxes (Details)

Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Effective tax rate (percent)			31.00%	(1.00%)
U.S. statutory rate (percent)			35.00%
Income Tax Examination [Line Items]
Foreign equity tax expense	$ 0	$ 0	$ 3,051,000	$ 3,769,000
National Taxes and Customs Direction (DIAN)
Income Tax Examination [Line Items]
Deferred tax recovery associated with the ceiling test adjustment			53,100,000
Colombia
Income Tax Examination [Line Items]
Unpaid equity tax liability	$ 1,600,000		$ 1,600,000		$ 0
Colombia | Tax Year 2015
Income Tax Examination [Line Items]
Equity tax rate (percent)			1.15%
Colombia | Tax Year 2016
Income Tax Examination [Line Items]
Equity tax rate (percent)			1.00%
Colombia | Tax Year 2017
Income Tax Examination [Line Items]
Equity tax rate (percent)			0.40%

Credit Facility (Details)

Credit Facility (Details) - USD ($) $ in Millions	Jun. 30, 2016	Jun. 02, 2016	Sep. 18, 2015
Line of Credit
Line of Credit Facility [Line Items]
Committed borrowing base under credit facility		$ 185	$ 200
Line of Credit | Readily available
Line of Credit Facility [Line Items]
Remaining borrowing capacity	$ 160
Line of Credit | Subject to consent
Line of Credit Facility [Line Items]
Remaining borrowing capacity	$ 25
Senior Notes
Line of Credit Facility [Line Items]
Committed borrowing base under credit facility		$ 500	$ 600

Contingencies (Details)

Contingencies (Details) $ in Millions	Apr. 30, 2015bbl	Jun. 30, 2016USD ($)	Dec. 31, 2015USD ($)
Loss Contingencies [Line Items]
Promissory notes provided as collateral for letters of credit		$ 72.4	$ 76.5
Settled Litigation Moqueta Discovery
Loss Contingencies [Line Items]
Total cumulative production of oil field (barrels) | bbl	5,000,000
Pending Litigation Royalty, Transportation and Related Costs | Maximum
Loss Contingencies [Line Items]
Contingent consideration liability		$ 45.2

Financial Instruments, Fair V52

Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk - Fair Value of Trading Securities and Contingent Consideration (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Trading securities	$ 3,979	$ 6,250
Derivatives, Fair Value [Line Items]
Assets, fair value disclosure	10,993	6,250
RSU and PSU liability	2,129	1,189
Commodity price
Derivatives, Fair Value [Line Items]
Derivative asset	5,896	0
Foreign currency
Derivatives, Fair Value [Line Items]
Derivative asset	$ 1,118	$ 0

Financial Instruments, Fair V53

Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk - Gains or Losses on Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Trading securities loss (gain)	$ 1,380	$ (1,688)	$ 2,225	$ (2,100)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative (gain) loss			(4,562)	0
Financial instruments gain	(1,072)	(1,366)	(227)	(1,408)
Commodity price
Derivative Instruments, Gain (Loss) [Line Items]
Derivative (gain) loss	(1,334)	0	(1,334)	0
Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative (gain) loss	$ (1,118)	$ 322	$ (1,118)	$ 692

Financial Instruments, Fair V54

Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk - Additional Information (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2016USD ($)$ / bbl	Dec. 31, 2015USD ($)
Fair Value Disclosures [Abstract]
Carrying amount of senior notes	$ 109,145	$ 0
Fair value of convertible debt	144,600
Premium on commodity price derivative	$ 4,600
Premium on commodity price derivative per barrel (in dollars per barrel) | $ / bbl	1.25

Financial Instruments, Fair V55

Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk - Schedule of Commodity Price Derivative Positions (Details) - Collar: June 1, 2016 to May 31, 2017 bbl in Thousands	6 Months Ended
	Jun. 30, 2016$ / bblbbl
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume, barrels of oil per day | bbl	10,000
Sold | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in dollars per barrel)	35,000
Sold | Call
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cap price (in dollars per barrel)	65,000
Purchased
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in dollars per barrel)	45,000

Financial Instruments, Fair V56

Financial Instruments, Fair Value Measurements, Credit Risk and Foreign Exchange Risk - Schedule of Foreign Currency Derivative Positions (Details)	Jun. 30, 2016COPCOP / collar
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged (in Colombian pesos) | COP	COP 110,084,000
Collar: June 1, 2016 to June 30, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged (in Colombian pesos) | COP	COP 9,794,600
Collar: June 1, 2016 to June 30, 2016 | Purchased
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cap price (in Colombian pesos)	3,000,000
Collar: June 1, 2016 to June 30, 2016 | Sold | Bank 1 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,265,000
Collar: June 1, 2016 to June 30, 2016 | Sold | Bank 2 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,310,000
Collar: July 1, 2016 to September 30, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged (in Colombian pesos) | COP	COP 25,064,600
Collar: July 1, 2016 to September 30, 2016 | Purchased
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cap price (in Colombian pesos)	3,000,000
Collar: July 1, 2016 to September 30, 2016 | Sold | Bank 1 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,275,000
Collar: July 1, 2016 to September 30, 2016 | Sold | Bank 2 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,320,000
Collar: October 1, 2016 to December 31, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged (in Colombian pesos) | COP	COP 20,930,000
Collar: October 1, 2016 to December 31, 2016 | Purchased
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cap price (in Colombian pesos)	3,000,000
Collar: October 1, 2016 to December 31, 2016 | Sold | Bank 1 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,285,000
Collar: October 1, 2016 to December 31, 2016 | Sold | Bank 2 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,330,000
Collar: January 1, 2017 to March 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged (in Colombian pesos) | COP	COP 31,597,600
Collar: January 1, 2017 to March 31, 2017 | Purchased
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cap price (in Colombian pesos)	3,100,000
Collar: January 1, 2017 to March 31, 2017 | Sold | Bank 1 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,300,000
Collar: January 1, 2017 to March 31, 2017 | Sold | Bank 2 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,345,000
Collar: April 1, 2017 to May 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged (in Colombian pesos) | COP	COP 22,697,200
Collar: April 1, 2017 to May 31, 2017 | Purchased
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cap price (in Colombian pesos)	3,100,000
Collar: April 1, 2017 to May 31, 2017 | Sold | Bank 1 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,310,000
Collar: April 1, 2017 to May 31, 2017 | Sold | Bank 2 | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in Colombian pesos)	3,370,000

Supplemental Cash Flow Inform57

Supplemental Cash Flow Information - Net Changes in Assets and Liabilities from Operating Activities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Supplemental Cash Flow Elements [Abstract]
Accounts receivable and other long-term assets	$ (9,156)	$ 23,652
Derivatives	(4,562)	0
Inventory	4,365	(7,697)
Prepaids	1,102	2,133
Accounts payable and accrued and other long-term liabilities	(5,628)	(20,319)
Taxes receivable and payable	7,249	(44,273)
Net changes in assets and liabilities from operating activities	$ (6,630)	$ (46,504)

Supplemental Cash Flow Inform58

Supplemental Cash Flow Information - Additional Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015
Supplemental Cash Flow Elements [Abstract]
Net liabilities related to property, plant and equipment, end of period	$ 24,497	$ 33,658

Subsequent Events (Details)

Subsequent Events (Details) - PetroLatina $ / shares in Units, shares in Millions	1 Months Ended	2 Months Ended	6 Months Ended
	Aug. 05, 2016USD ($)	Aug. 30, 2016USD ($)	Dec. 30, 2016USD ($)	Jul. 08, 2016USD ($)$ / sharesshares
Subsequent Event
Subsequent Event [Line Items]
Payment for acquisition	$ 5,000,000
New debt facility				$ 130,000,000
Subsequent Event | Common Stock
Subsequent Event [Line Items]
Subscription receipts issued (in shares) | shares				57.8
Subscription receipts, par value (in dollars per share) | $ / shares				$ 3
Subscription receipts, gross proceeds				$ 173,500,000
Subscription receipts, ratio of common shares received				1
Scenario, Forecast
Subsequent Event [Line Items]
Business combination, consideration transferred		$ 525,000,000
Payment for acquisition		$ 500,000,000	$ 25,000,000