Gran Tierra Energy (GTE) 10-Q 7 May 19 2019 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 03, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	GRAN TIERRA ENERGY INC.
Entity Central Index Key	0001273441
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		380,974,707
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Entity Emerging Growth	false
Entity Small Business	false

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
OIL AND NATURAL GAS SALES (Note 6)	$ 152,565	$ 138,228
EXPENSES
Operating	34,783	21,776
Workover	6,289	4,489
Transportation	8,103	6,997
Depletion, depreciation and accretion	62,921	39,461
General and administrative	9,596	11,160
Severance	672	0
Foreign exchange gain	(2,434)	(942)
Financial instruments loss (Note 9)	3,165	6,946
Interest expense (Note 4)	7,938	5,495
EXPENSES	131,033	95,382
INTEREST INCOME	133	786
INCOME BEFORE INCOME TAXES	21,665	43,632
INCOME TAX EXPENSE
Current (Note 7)	11,363	12,289
Deferred (Note 7)	8,323	13,482
INCOME TAX EXPENSE	19,686	25,771
NET AND COMPREHENSIVE INCOME	$ 1,979	$ 17,861
NET INCOME PER SHARE - BASIC and DILUTED (in dollars per share)	$ 0.01	$ 0.05
WEIGHTED AVERAGE SHARES OUTSTANDING - BASIC (Note 5) (in shares)	386,930,323	391,294,042
WEIGHTED AVERAGE SHARES OUTSTANDING - DILUTED (Note 5) (in shares)	386,945,682	391,379,013

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents (Note 10)	$ 32,740	$ 51,040
Restricted cash and cash equivalents (Note 10)	1,118	1,269
Accounts receivable	43,973	26,177
Investment (Note 9)	31,979	32,724
Taxes receivable	96,337	78,259
Other assets	14,344	13,056
Total Current Assets	220,491	202,525
Oil and Gas Properties (using the full cost method of accounting)
Proved	914,792	853,428
Unproved	523,621	456,598
Total Oil and Gas Properties	1,438,413	1,310,026
Other capital assets	6,023	2,751
Total Property, Plant and Equipment	1,444,436	1,312,777
Other Long-Term Assets
Deferred tax assets	44,126	45,437
Investment (Note 9)	8,513	8,711
Other	4,601	4,553
Goodwill	102,581	102,581
Total Other Long-Term Assets	159,821	161,282
Total Assets	1,824,748	1,676,584
Current Liabilities
Accounts payable and accrued liabilities	186,736	154,670
Derivatives (Note 9)	1,194	1,017
Taxes payable	3,883	4,149
Equity compensation award liability (Note 5)	5,388	9,544
Total Current Liabilities	197,201	169,380
Long-Term Liabilities
Long-term debt (Notes 4 and 9)	516,916	399,415
Deferred tax liabilities	29,813	23,419
Asset retirement obligation	43,007	43,676
Equity compensation award liability (Note 5)	4,593	8,139
Other	7,559	2,805
Total Long-Term Liabilities	601,888	477,454
Contingencies (Note 8)
Shareholders’ Equity
Common Stock (Note 5) (384,492,732 and 387,079,027 shares of Common Stock par value $0.001 per share, issued and outstanding as at March 31, 2019, and December 31, 2018, respectively)	10,287	10,290
Additional paid in capital	1,312,371	1,318,048
Deficit	(296,999)	(298,588)
Total Shareholders’ Equity	1,025,659	1,029,750
Total Liabilities and Shareholders’ Equity	$ 1,824,748	$ 1,676,584

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common Stock, shares issued (in shares)	384,492,732	387,079,027
Common Stock, shares outstanding (in shares)	384,492,732	387,079,027
Common Stock and exchangeable shares, par value (in dollars per share)	$ 0.001	$ 0.001

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Activities
Net income	$ 1,979	$ 17,861
Adjustments to reconcile net income to net cash provided by operating activities:
Depletion, depreciation and accretion	62,921	39,461
Deferred tax expense	8,323	13,482
Stock-based compensation (Note 5)	1,727	3,309
Amortization of debt issuance costs (Note 4)	838	670
Unrealized foreign exchange gain	(3,283)	(1,044)
Financial instruments loss (Note 9)	3,165	6,946
Cash settlement of financial instruments (Note 9)	(220)	(5,817)
Cash settlement of asset retirement obligation	(217)	(192)
Cash settlement of restricted share units	0	(120)
Net change in assets and liabilities from operating activities (Note 10)	(29,950)	(3,464)
Net cash provided by operating activities	45,283	71,092
Investing Activities
Additions to property, plant and equipment	(94,489)	(72,694)
Property acquisitions, net of cash acquired (Note 3)	(73,827)	0
Changes in non-cash investing working capital	(2,166)	1,957
Net cash used in investing activities	$ (170,482)	(70,737)
Exercised (in dollars per share)	$ 0
Financing Activities
Proceeds from bank debt, net of issuance costs	$ 117,000	4,988
Repayment of bank debt	(3,000)	(153,000)
Lease Payments	(345)	0
Repurchase of shares of Common Stock (Note 5)	(6,154)	(1,194)
Proceeds from exercise of stock options	0	74
Proceeds from issuance of Senior Notes, net of issuance costs	0	288,368
Net cash provided by financing activities	107,501	139,236
Foreign exchange loss on cash, cash equivalents and restricted cash and cash equivalents	(486)	663
Net (decrease) increase in cash, cash equivalents and restricted cash and cash equivalents	(18,184)	140,254
Cash, cash equivalents and restricted cash and cash equivalents, beginning of period (Note 10)	54,308	26,678
Cash, cash equivalents and restricted cash and cash equivalents, end of period (Note 10)	$ 36,124	$ 166,932

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Share Capital	Additional Paid in Capital	Deficit
Increase (Decrease) in Stockholders' Equity
Cumulative adjustment for accounting change related to leases (Note 2)				$ 0
Balance, beginning of period at Dec. 31, 2017		$ 10,295	$ 1,327,244	(401,204)
Increase (Decrease) in Stockholders' Equity
Repurchase of Common Stock (Note 5)		0	(1,194)
Exercise of stock options			74
Stock-based compensation (Note 5)			563
Net income	$ 17,861			17,861
Balance, end of period at Mar. 31, 2018	953,639	10,295	1,326,687	(383,343)
Increase (Decrease) in Stockholders' Equity
Cumulative adjustment for accounting change related to leases (Note 2)				(390)
Balance, beginning of period at Dec. 31, 2018		10,290	1,318,048	(298,588)
Increase (Decrease) in Stockholders' Equity
Repurchase of Common Stock (Note 5)		(3)	(6,151)
Exercise of stock options			0
Stock-based compensation (Note 5)			474
Net income	1,979			1,979
Balance, end of period at Mar. 31, 2019	$ 1,025,659	$ 10,287	$ 1,312,371	$ (296,999)

Description of Business

Description of Business	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Gran Tierra Energy Inc., a Delaware corporation (the “Company” or “Gran Tierra”), is a publicly traded company focused on oil and natural gas exploration and production in Colombia and Ecuador.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
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, 2018 , included in the Company’s 2018 Annual Report on Form 10-K. The Company’s significant accounting policies are described in Note 2 of the consolidated financial statements which are included in the Company’s 2018 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. Recently Adopted Accounting Pronouncements Leases The Company adopted Accounting Standard Codification ("ASC") 842 Leases with a date of initial application on January 1, 2019 in accordance with the modified retrospective transition approach using the practical expedients available for land easements and short-term leases. The Company did not elect the "suite" of practical expedients or use the hindsight expedient in its adoption. At inception of a contract, the Company assesses whether a contract is, or contains, a lease. A contract is, or contains, a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. At inception of a contract that contains a lease component, the Company allocates the consideration in the contract to each lease and non-lease component on the basis of their relative stand-alone prices. The Company recognizes a right-of-use asset and a lease liability at the lease commencement date. The right-of-use asset is initially measured at cost, and subsequently at cost less any accumulated depreciation and impairment losses, and adjusted for certain remeasurements of the lease liability. The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted using the interest rate implicit in the lease or, if that rate cannot be readily determined, the Company's incremental borrowing rate. Generally, the Company uses its incremental borrowing rate as the discount rate. The lease liability is subsequently increased by the interest cost on the lease liability and decreased by lease payments made. It is remeasured when there is a change in future lease payments arising from a change in an index or rate, a change in the estimate of the amount expected to be payable under a residual value guarantee, or as appropriate, changes in the assessment of whether a purchase or extension option is reasonably certain to be exercised or a termination option is reasonably certain not to be exercised. The Company has applied judgment to determine the lease term for contracts which include renewal or termination options. The assessment of whether the Company is reasonably certain to exercise such options impacts the lease term, which significantly affects the amount of lease liabilities and right-of-use assets recognized. All leases identified relate to office leases. The transition resulted in the recognition of a right-of-use asset presented in other capital assets of $3.8 million at January 1, 2019, the recognition of lease liabilities of $4.2 million and a $0.4 million impact on retained earnings. When measuring the lease liabilities, the Company's incremental borrowing rate was used. At January 1, 2019 the rates applied ranged between 5.6% and 9.1% .

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment On February 20, 2019, the Company acquired 36.2% working interest ("WI") in the Suroriente Block and a 100% WI of the Llanos-5 Block for cash consideration of $79.1 million and a promissory note of $1.5 million included in current accounts payable on the Company's condensed consolidated balance sheet. The cost of the assets was allocated to proved assets using relative fair values. The entire consideration of $0.3 million for Llanos-5 was allocated to unproved assets. (Thousands of U.S. Dollars) Cost of asset acquisition: Cash $ 79,100 Promissory note 1,500 $ 80,600 Allocation of Consideration Paid: Oil and gas properties Proved $ 52,340 Unproved 44,608 96,948 Net working capital (including cash acquired of $5.3 million) (16,348 ) $ 80,600 Subsequent to the quarter, the Company acquired the remaining 20% WI of the VMM-2 Block for cash consideration of $3.5 million .

Debt and Debt Issuance Costs

Debt and Debt Issuance Costs	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt and Debt Issuance Costs	Debt and Debt Issuance Costs The Company's debt at March 31, 2019 and December 31, 2018 was as follows: (Thousands of U.S. Dollars) As at March 31, 2019 As at December 31, 2018 Senior notes $ 300,000 $ 300,000 Convertible notes 115,000 115,000 Revolving credit facility 114,000 — Unamortized debt issuance costs (14,747 ) (15,585 ) Long-term debt 514,253 399,415 Long-term lease obligation (1) 2,663 — $ 516,916 $ 399,415 (1) The current portion of the lease obligation has been included in Accounts Payable and totaled $1.8 million as at March 31, 2019 ( nil - December 31, 2018 ). Interest Expense The following table presents total interest expense recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Contractual interest and other financing expenses $ 7,100 $ 4,825 Amortization of debt issuance costs 838 670 $ 7,938 $ 5,495

Share Capital

Share Capital	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Capital	Share Capital Shares of Common Stock Balance, December 31, 2018 387,079,027 Shares repurchased and canceled (2,586,295 ) Balance, March 31, 2019 384,492,732 On March 11, 2019 , the Company announced that it intended to implement a share repurchase program (the “2019 Program”) through the facilities of the Toronto Stock Exchange ("TSX") and eligible alternative trading platforms in Canada. Under the 2019 Program, the Company is able to purchase at prevailing market prices up to 19,353,951 shares of Common Stock, representing approximately 5.00% of the issued and outstanding shares of Common Stock as of March 1, 2019 . Shares purchased pursuant to 2019 Program will be canceled. The 2019 Program will expire on March 12, 2020 , or earlier if the 5.00% share maximum is reached. During three months ended March 31, 2019 , the Company repurchased 743,520 shares at a weighted average price of $2.34 under 2018 share repurchase program and 1,842,775 shares at a weighted average price of $2.40 per share under the 2019 Program. All the repurchased shares were canceled subsequent to repurchase. Equity Compensation Awards The following table provides information about p erformance stock units (“PSUs”), deferred share units (“DSUs”), and stock option activity for the three months ended March 31, 2019 : PSUs DSUs Stock Options Number of Outstanding Share Units Number of Outstanding Share Units Number of Outstanding Stock Options Weighted Average Exercise Price/Stock Option ($) Balance, December 31, 2018 9,004,661 684,893 9,034,412 3.18 Granted 4,382,335 83,072 2,083,026 2.32 Exercised (2,725,877 ) — — — Forfeited (457,290 ) — (477,691 ) 4.56 Expired — — (44,940 ) 7.09 Balance, March 31, 2019 10,203,829 767,965 10,594,807 2.93 Stock-based compensation expense for the three months ended March 31, 2019 , was $1.7 million ( three months ended March 31, 2018 - $3.3 million ). At March 31, 2019 , there was $18.1 million ( December 31, 2018 - $9.2 million ) of unrecognized compensation cost related to unvested PSUs and stock options which is expected to be recognized over a weighted average period of 2.1 years. For the three months ended March 31, 2019 , the Company paid out $10.2 million ( three months ended March 31, 2018 - $0.0 million ) for performance share units which were vested December 31, 2018 . Net Income per Share Basic net income per share is calculated by dividing net income by the weighted average number of shares of Common Stock and exchangeable shares issued and outstanding during each period. Diluted net income per share is similarly calculated except that the common shares outstanding for the period is increased using the treasury stock method to reflect the potential dilution that could occur if outstanding stock awards were vested at the end of the applicable period plus potentially issuable shares on conversion of the convertible notes. Anti-dilutive shares represent potentially dilutive securities that are excluded from the computation of diluted income or loss per share as their impact would be anti-dilutive. Weighted Average Shares Outstanding Three Months Ended March 31, 2019 2018 Weighted average number of common and exchangeable shares outstanding 386,930,323 391,294,042 Shares issuable pursuant to stock options 333,028 867,427 Shares assumed to be purchased from proceeds of stock options (317,669 ) (782,456 ) Weighted average number of diluted common and exchangeable shares outstanding 386,945,682 391,379,013 For the three months ended March 31, 2019 , 10,284,152 options ( three months ended March 31, 2018 - 8,599,422 ), on a weighted average basis, were excluded from the diluted income per share calculation as the options were anti-dilutive. Shares issuable upon conversion of the 5.00% Convertible Notes due 2021 ("Convertible Notes") were anti-dilutive and not included in the diluted income per share calculation.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Most of the Company's revenues are from oil sales at prices which reflect the blended prices received upon shipment by the purchaser at defined sales points or are defined by contract relative to ICE Brent and adjusted for Vasconia crude, quality and transportation discounts each month. For the three months ended March 31, 2019 , 100% ( three months ended March 31, 2018 - 100% ) of the Company's revenue resulted from oil sales. During the three months ended March 31, 2019 , quality and transportation discounts were 17% of the average ICE Brent price ( three months ended March 31, 2018 - 16% ). During the three months ended March 31, 2019 , the Company's production was sold primarily to two major customers in Colombia ( three months ended March 31, 2018 - four ). As at March 31, 2019 , accounts receivable included $4.3 million of accrued sales revenue related to March 2019 production ( December 31, 2018 - $4.2 million related to December 31, 2018 production).

Taxes

Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Taxes	Taxes The Company's effective tax rate was 91% in the three months ended March 31, 2019 , compared with 59% in the comparative period in 2018 . Current income tax expenses were lower in the three months ended March 31, 2019 , compared with the corresponding period in 2018 , primarily as a result of lower taxable income in Colombia. The deferred income tax expense of $8.3 million for the three months ended March 31, 2019 was primarily due to excess tax depreciation compared with accounting depreciation in Colombia. For the three months ended March 31, 2019 , the difference between the effective tax rate of 91% and the 33% Colombian tax rate was primarily due to an increase in the valuation allowance, foreign translation adjustment, a non-deductible third party royalty in Colombia, stock-based compensation and other permanent differences. These were partially offset by a decrease in the impact of foreign taxes. For the comparative period in 2018 , the 59% effective tax rate differed from the Colombian tax rate of 37% primarily due to an increase to the valuation allowance, non-deductible third party royalty in Colombia, stock based compensation, foreign currency translation and other permanent differences. These were partially offset by a decrease in the impact of foreign taxes.

Contingencies

Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies The Agencia Nacional de Hidrocarburos (National Hydrocarbons Agency) ("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 an additional royalty (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 $55.6 million as at March 31, 2019 . 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. In addition to the above, the Company has a number of other lawsuits and claims pending. Although the outcome of these other lawsuits and disputes cannot be predicted with certainty, the Company 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 associated with these lawsuits and claims as they are incurred or become probable and determinable. Letters of credit and other credit support At March 31, 2019 , the Company had provided letters of credit and other credit support totaling $77.1 million ( December 31, 2018 - $76.7 million ) as security relating to work commitment guarantees contained in exploration contracts and other capital or operating requirements.

Financial Instruments and Fair

Financial Instruments and Fair Value Measurement	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurement	Financial Instruments and Fair Value Measurement Financial Instruments At March 31, 2019 , the Company’s financial instruments recognized in the balance sheet consisted of: cash and cash equivalents; restricted cash and cash equivalents; accounts receivable; investment; derivatives, accounts payable and accrued liabilities, long-term debt, equity compensation award liability and other long-term liabilities. Fair Value Measurement The fair value of investment, derivatives and PSU liabilities is remeasured at the estimated fair value at the end of each reporting period. The fair value of the short-term portion of the Company's investment in PetroTal Corp. ("PetroTal"), which was received on the sale of the Company's Peru business unit, was estimated using quoted prices at March 31, 2019 , and the foreign exchange rate at that date. The fair value of the long-term portion of the investment restricted by escrow conditions was estimated using observable and unobservable inputs; factors that were evaluated included quoted market prices, precedent comparable transactions, risk free rate, measures of market risk volatility, estimates of the Company's and PetroTal’s cost of capital and quotes from third parties. 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 PSU liability was estimated based on option pricing model using inputs such as quoted market prices in an active market, and PSU performance factor. The fair value of investment, derivatives, PSU and DSU liabilities at March 31, 2019 , and December 31, 2018 , was as follows: (Thousands of U.S. Dollars) As at March 31, 2019 As at December 31, 2018 Investment - current and long-term $ 40,491 $ 41,435 Derivative liability $ 1,194 $ 1,017 DSU and PSU liability 9,982 17,683 $ 11,176 $ 18,700 The following table presents gains or losses on financial instruments recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Commodity price derivative loss $ 1,194 $ 4,995 Foreign currency derivatives gain — (3,970 ) Investment loss 1,971 5,921 Financial instruments loss $ 3,165 $ 6,946 These losses are presented as financial instruments loss in the condensed consolidated statements of operations and cash flows. Investment loss for the three months ended March 31, 2019 , related to the fair value loss on the PetroTal shares Gran Tierra received in connection with the sale of its Peru business unit in December 2017. For the three months ended March 31, 2019 and 2018 , this investment loss was unrealized. Financial instruments not recorded at fair value include the Company's 6.25% Senior Notes due 2025 (the "Senior Notes") and the Convertible Notes (Note 4). At March 31, 2019 , the carrying amounts of the Senior Notes and the Convertible Notes were $289.6 million and $112.4 million , respectively, which represented the aggregate principal amount less unamortized debt issuance costs, and the fair values were $286.8 million and $119.0 million , respectively. The fair value of long-term restricted cash and cash equivalents and the revolving credit facility approximated their carrying value because interest rates are variable and reflective of market rates. The fair values of other financial instruments approximate their carrying amounts due to the short-term maturity of these instruments. GAAP establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. This hierarchy consists of three broad levels. Level 1 inputs consist of quoted prices (unadjusted) in active markets for identical assets and liabilities and have the highest priority. Level 2 and 3 inputs are based on significant other observable inputs and significant unobservable inputs, respectively, and have lower priorities. The Company uses appropriate valuation techniques based on the available inputs to measure the fair values of assets and liabilities. At March 31, 2019 , the fair value of the current portion of the investment and DSU liability was determined using Level 1 inputs, the fair value of derivatives and PSUs was determined using Level 2 inputs and the fair value of the long-term portion of the investment restricted by escrow conditions was determined using Level 3 inputs. The table below presents the fair value of the long-term portion of the investment: Three Months Ended Year Ended (Thousands of U.S. Dollars) March 31, 2019 December 31, 2018 Opening balance, investment - long-term $ 8,711 $ 19,147 Transfer from long-term (Level 3) to current (Level 1) — (10,522 ) Unrealized valuation (loss) gain (417 ) 846 Unrealized foreign exchange gain (loss) 219 (760 ) Closing balance, investment - long-term $ 8,513 $ 8,711 The Company uses available market data and valuation methodologies to estimate the fair value of debt. The fair value of debt is the estimated amount the Company would have to pay a third party to assume the debt, including a credit spread for the difference between the issue rate and the period end market rate. The credit spread is the Company’s default or repayment risk. The credit spread (premium or discount) is determined by comparing the Company’s Senior Notes, Convertible Notes and revolving credit facility to new issuances (secured and unsecured) and secondary trades of similar size and credit statistics for both public and private debt. The disclosure above regarding the fair value of the Convertible Notes was determined using Level 2 inputs based on the indicative pricing published by certain third-party services or trading levels of the Convertible 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 and cash equivalents, revolving credit facility and Senior Notes 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 March 31, 2019 , the Company had outstanding commodity price derivative positions as follows: Period and type of instrument Volume, Reference Purchased Put ($/bbl, Weighted Average) Sold Call ($/bbl, Weighted Average) Premium ($/bbl, Weighted Average) Purchased Puts: April 1, to December 31, 2019 5,000 ICE Brent $ 60.00 n/a $ 2.39 Collars: April 1, to December 31, 2019 5,000 ICE Brent $ 60.00 $ 71.53 n/a 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 expenses. Subsequent to March 31, 2019 , the Company entered into foreign currency derivative positions as follows: Period and type of instrument Amount Hedged U.S. Dollar Equivalent of Amount Hedged (Thousands of U.S. Dollars) (1) Reference Floor Price Cap Price (COP, Weighted Average) Collars: May 1, to December 31, 2019 180,000 56,697 COP 3,019 3,446 (1) At March 31, 2019 foreign exchange rate.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information The following table provides a reconciliation of cash, cash equivalents and restricted cash and cash equivalents with the Company's interim unaudited condensed consolidated balance sheet that sum to the total of the same such amounts shown in the interim unaudited condensed consolidated statements of cash flows: (Thousands of U.S. Dollars) As at March 31, As at December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 32,740 $ 160,474 $ 51,040 $ 12,326 Restricted cash and cash equivalents - current 1,118 3,294 1,269 11,787 Restricted cash and cash equivalents - long-term (included in other long-term assets) 2,266 3,164 1,999 2,565 $ 36,124 $ 166,932 $ 54,308 $ 26,678 Net changes in assets and liabilities from operating activities were as follows: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Accounts receivable and other long-term assets $ (18,011 ) $ (1,982 ) Derivatives (796 ) 1,847 Inventory (1,749 ) (1,785 ) Prepaids 551 1,498 Accounts payable and accrued and other long-term liabilities 6,456 (2,495 ) Taxes receivable and payable (16,401 ) (547 ) Net changes in assets and liabilities from operating activities $ (29,950 ) $ (3,464 ) The following table provides additional supplemental cash flow disclosures: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Non-cash investing activities: Net liabilities related to property, plant and equipment, end of period $ 83,038 $ 70,108

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Recently Adopted Accounting Pronouncements/Recently Issued but Not Yet Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Leases The Company adopted Accounting Standard Codification ("ASC") 842 Leases with a date of initial application on January 1, 2019 in accordance with the modified retrospective transition approach using the practical expedients available for land easements and short-term leases. The Company did not elect the "suite" of practical expedients or use the hindsight expedient in its adoption. At inception of a contract, the Company assesses whether a contract is, or contains, a lease. A contract is, or contains, a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. At inception of a contract that contains a lease component, the Company allocates the consideration in the contract to each lease and non-lease component on the basis of their relative stand-alone prices. The Company recognizes a right-of-use asset and a lease liability at the lease commencement date. The right-of-use asset is initially measured at cost, and subsequently at cost less any accumulated depreciation and impairment losses, and adjusted for certain remeasurements of the lease liability. The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted using the interest rate implicit in the lease or, if that rate cannot be readily determined, the Company's incremental borrowing rate. Generally, the Company uses its incremental borrowing rate as the discount rate. The lease liability is subsequently increased by the interest cost on the lease liability and decreased by lease payments made. It is remeasured when there is a change in future lease payments arising from a change in an index or rate, a change in the estimate of the amount expected to be payable under a residual value guarantee, or as appropriate, changes in the assessment of whether a purchase or extension option is reasonably certain to be exercised or a termination option is reasonably certain not to be exercised. The Company has applied judgment to determine the lease term for contracts which include renewal or termination options. The assessment of whether the Company is reasonably certain to exercise such options impacts the lease term, which significantly affects the amount of lease liabilities and right-of-use assets recognized. All leases identified relate to office leases. The transition resulted in the recognition of a right-of-use asset presented in other capital assets of $3.8 million at January 1, 2019, the recognition of lease liabilities of $4.2 million and a $0.4 million impact on retained earnings. When measuring the lease liabilities, the Company's incremental borrowing rate was used. At January 1, 2019 the rates applied ranged between 5.6% and 9.1% .

Property, Plant and Equipment P

Property, Plant and Equipment Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	(Thousands of U.S. Dollars) Cost of asset acquisition: Cash $ 79,100 Promissory note 1,500 $ 80,600 Allocation of Consideration Paid: Oil and gas properties Proved $ 52,340 Unproved 44,608 96,948 Net working capital (including cash acquired of $5.3 million) (16,348 ) $ 80,600

Debt and Debt Issuance Costs (T

Debt and Debt Issuance Costs (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt	The Company's debt at March 31, 2019 and December 31, 2018 was as follows: (Thousands of U.S. Dollars) As at March 31, 2019 As at December 31, 2018 Senior notes $ 300,000 $ 300,000 Convertible notes 115,000 115,000 Revolving credit facility 114,000 — Unamortized debt issuance costs (14,747 ) (15,585 ) Long-term debt 514,253 399,415 Long-term lease obligation (1) 2,663 — $ 516,916 $ 399,415 (1) The current portion of the lease obligation has been included in Accounts Payable and totaled $1.8 million as at March 31, 2019 ( nil - December 31, 2018 ).
Schedule of Interest Expense Recognized	The following table presents total interest expense recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Contractual interest and other financing expenses $ 7,100 $ 4,825 Amortization of debt issuance costs 838 670 $ 7,938 $ 5,495

Share Capital (Tables)

Share Capital (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Common Stock	Shares of Common Stock Balance, December 31, 2018 387,079,027 Shares repurchased and canceled (2,586,295 ) Balance, March 31, 2019 384,492,732
Schedule of PSU, DSU, RSU and Stock Option Activity	The following table provides information about p erformance stock units (“PSUs”), deferred share units (“DSUs”), and stock option activity for the three months ended March 31, 2019 : PSUs DSUs Stock Options Number of Outstanding Share Units Number of Outstanding Share Units Number of Outstanding Stock Options Weighted Average Exercise Price/Stock Option ($) Balance, December 31, 2018 9,004,661 684,893 9,034,412 3.18 Granted 4,382,335 83,072 2,083,026 2.32 Exercised (2,725,877 ) — — — Forfeited (457,290 ) — (477,691 ) 4.56 Expired — — (44,940 ) 7.09 Balance, March 31, 2019 10,203,829 767,965 10,594,807 2.93
Schedule of Weighted Average Shares Outstanding	Weighted Average Shares Outstanding Three Months Ended March 31, 2019 2018 Weighted average number of common and exchangeable shares outstanding 386,930,323 391,294,042 Shares issuable pursuant to stock options 333,028 867,427 Shares assumed to be purchased from proceeds of stock options (317,669 ) (782,456 ) Weighted average number of diluted common and exchangeable shares outstanding 386,945,682 391,379,013

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurement (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Derivatives and RSU, PSU and DSU Liabilities	The fair value of investment, derivatives, PSU and DSU liabilities at March 31, 2019 , and December 31, 2018 , was as follows: (Thousands of U.S. Dollars) As at March 31, 2019 As at December 31, 2018 Investment - current and long-term $ 40,491 $ 41,435 Derivative liability $ 1,194 $ 1,017 DSU and PSU liability 9,982 17,683 $ 11,176 $ 18,700
Schedule of Gains or Losses on Financial Instruments Recognized	The following table presents gains or losses on financial instruments recognized in the accompanying interim unaudited condensed consolidated statements of operations: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Commodity price derivative loss $ 1,194 $ 4,995 Foreign currency derivatives gain — (3,970 ) Investment loss 1,971 5,921 Financial instruments loss $ 3,165 $ 6,946
Schedule of Fair Value of Long-term Investments	The table below presents the fair value of the long-term portion of the investment: Three Months Ended Year Ended (Thousands of U.S. Dollars) March 31, 2019 December 31, 2018 Opening balance, investment - long-term $ 8,711 $ 19,147 Transfer from long-term (Level 3) to current (Level 1) — (10,522 ) Unrealized valuation (loss) gain (417 ) 846 Unrealized foreign exchange gain (loss) 219 (760 ) Closing balance, investment - long-term $ 8,513 $ 8,711
Schedule of Commodity Price Derivative Positions and Commodity Foreign Currency Contracts	At March 31, 2019 , the Company had outstanding commodity price derivative positions as follows: Period and type of instrument Volume, Reference Purchased Put ($/bbl, Weighted Average) Sold Call ($/bbl, Weighted Average) Premium ($/bbl, Weighted Average) Purchased Puts: April 1, to December 31, 2019 5,000 ICE Brent $ 60.00 n/a $ 2.39 Collars: April 1, to December 31, 2019 5,000 ICE Brent $ 60.00 $ 71.53 n/a
Schedule of Outstanding Foreign Currency Derivative Positions	Subsequent to March 31, 2019 , the Company entered into foreign currency derivative positions as follows: Period and type of instrument Amount Hedged U.S. Dollar Equivalent of Amount Hedged (Thousands of U.S. Dollars) (1) Reference Floor Price Cap Price (COP, Weighted Average) Collars: May 1, to December 31, 2019 180,000 56,697 COP 3,019 3,446 (1) At March 31, 2019 foreign exchange rate.

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Reconciliation of Cash, Cash Equivalents and Restricted Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash and cash equivalents with the Company's interim unaudited condensed consolidated balance sheet that sum to the total of the same such amounts shown in the interim unaudited condensed consolidated statements of cash flows: (Thousands of U.S. Dollars) As at March 31, As at December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 32,740 $ 160,474 $ 51,040 $ 12,326 Restricted cash and cash equivalents - current 1,118 3,294 1,269 11,787 Restricted cash and cash equivalents - long-term (included in other long-term assets) 2,266 3,164 1,999 2,565 $ 36,124 $ 166,932 $ 54,308 $ 26,678
Schedule of Net Changes in Assets and Liabilities	Net changes in assets and liabilities from operating activities were as follows: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Accounts receivable and other long-term assets $ (18,011 ) $ (1,982 ) Derivatives (796 ) 1,847 Inventory (1,749 ) (1,785 ) Prepaids 551 1,498 Accounts payable and accrued and other long-term liabilities 6,456 (2,495 ) Taxes receivable and payable (16,401 ) (547 ) Net changes in assets and liabilities from operating activities $ (29,950 ) $ (3,464 )
Schedule of Additional Supplemental Cash Flow Disclosures	The following table provides additional supplemental cash flow disclosures: Three Months Ended March 31, (Thousands of U.S. Dollars) 2019 2018 Non-cash investing activities: Net liabilities related to property, plant and equipment, end of period $ 83,038 $ 70,108

Significant Accounting Polici_3

Significant Accounting Policies (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Right-of-use asset		$ 3,800
Lease liabilities		(4,200)
Retained Earnings	$ (296,999)	$ 400	$ (298,588)
Minimum
Lessee, Lease, Description [Line Items]
Weighted average discount rate, percent		5.60%
Maximum
Lessee, Lease, Description [Line Items]
Weighted average discount rate, percent		9.10%

Property, Plant and Equipment -

Property, Plant and Equipment - Narrative (Details) - USD ($) $ in Millions	May 07, 2019	Feb. 20, 2019
Suroriente block
Property, Plant and Equipment [Line Items]
Business acquisition, percentage of working interests acquired		36.20%
Llanos-5 Block
Property, Plant and Equipment [Line Items]
Business acquisition, percentage of working interests acquired		100.00%
Llanos-5 Block | Unproved
Property, Plant and Equipment [Line Items]
Payments to acquire oil and gas property		$ 0.3
Suroriente and Llanos-5
Property, Plant and Equipment [Line Items]
Payments to acquire oil and gas property		79.1
Suroriente and Llanos-5 | Accounts payable
Property, Plant and Equipment [Line Items]
Promissory notes		$ 1.5
VMM-2 Block | Subsequent Event
Property, Plant and Equipment [Line Items]
Business acquisition, percentage of working interests acquired	20.00%
Payments to acquire oil and gas property	$ 3.5

Property, Plant and Equipment_2

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Feb. 20, 2019	Mar. 31, 2019	Dec. 31, 2018
Cost of asset acquisition:
Property, plant and equipment, gross	$ 96,948
Accumulated depletion and depreciation	(16,348)
Total Property, Plant and Equipment	80,600	$ 1,444,436	$ 1,312,777
Cash acquired	5,300
Oil and natural gas properties
Cost of asset acquisition:
Cash	79,100
Promissory note	1,500
Consideration transferred	80,600
Proved
Cost of asset acquisition:
Property, plant and equipment, gross	52,340
Unproved
Cost of asset acquisition:
Property, plant and equipment, gross	$ 44,608

Debt and Debt Issuance Costs -

Debt and Debt Issuance Costs - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (14,747)	$ (15,585)
Long-term debt	514,253	399,415
Long-term debt excluding current maturity	516,916	399,415
Senior notes | Senior Notes Unsecured 6.25%
Debt Instrument [Line Items]
Convertible senior notes and revolving credit facility	300,000	300,000
Convertible notes
Debt Instrument [Line Items]
Convertible senior notes and revolving credit facility	115,000	115,000
Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Convertible senior notes and revolving credit facility	114,000	0
Lease obligations
Debt Instrument [Line Items]
Long-term lease obligation	2,663	0
Lease obligations | Accounts payable
Debt Instrument [Line Items]
Current portion of lease obligation	$ 1,800	$ 0

Debt and Debt Issuance Costs _2

Debt and Debt Issuance Costs - Schedule of Interest Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Debt Disclosure [Abstract]
Contractual interest and other financing expenses	$ 7,100	$ 4,825
Amortization of debt issuance costs	838	670
Total interest expense recognized	$ 7,938	$ 5,495

Share Capital - Schedule of Com

Share Capital - Schedule of Common Stock (Details)	3 Months Ended
	Mar. 31, 2019shares
Increase (Decrease) in Common Stock
Beginning balance (in shares)	387,079,027
Ending balance (in shares)	384,492,732
Shares of Common Stock
Increase (Decrease) in Common Stock
Beginning balance (in shares)	387,079,027
Shares repurchased and canceled (in shares)	(2,586,295)
Ending balance (in shares)	384,492,732

Share Capital - Additional Info

Share Capital - Additional Information (Details) - $ / shares	Mar. 13, 2019	Mar. 31, 2019
The Program 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchased during period (in shares)		743,520
Stock repurchased during period, weighted average price (in dollars per shares)		$ 2.34
The 2019 Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under the 2018 Program (up to) (in shares)	19,353,951
Shares authorized representing issued and outstanding shares of Common Stock (as a percent)	5.00%
Stock repurchased during period (in shares)		1,842,775
Stock repurchased during period, weighted average price (in dollars per shares)		$ 2.40

Share Capital - Schedule of PSU

Share Capital - Schedule of PSU, DSU, RSU and Stock Option Activity (Details)	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Number of Outstanding Stock Options
Beginning Balance (in shares)	9,034,412
Granted (in shares)	2,083,026
Exercised (in shares)	0
Forfeited (in shares)	(477,691)
Expired (in shares)	(44,940)
Ending Balance (in shares)	10,594,807
Weighted Average Exercise Price/Stock Option ($)
Beginning balance (in dollars per share) | $ / shares	$ 3.18
Granted (in dollars per share) | $ / shares	2.32
Forfeited (in dollars per share) | $ / shares	4.56
Expired (in dollars per share) | $ / shares	7.09
Ending balance (in dollars per share) | $ / shares	$ 2.93
PSUs
Number of Outstanding Share Units
Beginning Balance (in shares)	9,004,661
Granted (in shares)	4,382,335
Exercised (in shares)	(2,725,877)
Forfeited (in shares)	(457,290)
Expired (in shares)	0
Ending Balance (in shares)	10,203,829
DSUs
Number of Outstanding Share Units
Beginning Balance (in shares)	684,893
Granted (in shares)	83,072
Exercised (in shares)	0
Forfeited (in shares)	0
Expired (in shares)	0
Ending Balance (in shares)	767,965

Share Capital - Equity Compensa

Share Capital - Equity Compensation Awards (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 1,727	$ 3,309
Unrecognized compensation cost	$ 18,100		$ 9,200
Weighted average period for recognition	2 years 1 month 14 days
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payments for units vested in period	$ 10,200	0
General and administrative (G&A) expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 1,700	$ 3,300

Share Capital - Schedule of Wei

Share Capital - Schedule of Weighted Average Shares Outstanding (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average number of common and exchangeable shares outstanding (in shares)	386,930,323	391,294,042
Shares issuable pursuant to stock options (in shares)	333,028	867,427
Shares assumed to be purchased from proceeds of stock options (in shares)	(317,669)	(782,456)
Weighted average number of diluted common and exchangeable shares outstanding (in shares)	386,945,682	391,379,013

Share Capital - Weighted Averag

Share Capital - Weighted Average Shares Outstanding (Narrative) (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Convertible notes | Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stated interest rate	5.00%
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options excluded from diluted income (loss) per share calculation (in shares)	10,284,152	8,599,422

Revenue (Details)

Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Concentration Risk [Line Items]
Variable adjustment for transportation, location, quality, and other elements, percentage	17.00%	16.00%
Accrued sales revenue	$ 4.3		$ 4.2
Product Concentration Risk | Revenue from Contract with Customer
Concentration Risk [Line Items]
Concentration risk, percentage	100.00%	100.00%

Taxes (Details)

Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Contingency [Line Items]
Effective tax rate	91.00%	59.00%
Deferred tax expense	$ (8,323)	$ (13,482)
Colombia
Income Tax Contingency [Line Items]
Effective tax rate	33.00%	37.00%

Contingencies (Details)

Contingencies (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Letters of credit and other credit support provided	$ 77,100,000	$ 76,700,000
Pending Litigation Royalty, Transportation and Related Costs
Loss Contingencies [Line Items]
Estimated compensation which would be payable if the ANH's interpretation is correct	55,600,000
Amount accrued	$ 0

Financial Instruments and Fai_3

Financial Instruments and Fair Value Measurement - Schedule of Fair Value of Derivatives and RSU, PSU and DSU Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Investment - current and long-term	$ 40,491	$ 41,435
Derivative liability	1,194	1,017
DSU and PSU liability	9,982	17,683
Liabilities, fair value disclosure	$ 11,176	$ 18,700

Financial Instruments and Fai_4

Financial Instruments and Fair Value Measurement - Schedule of Gains or Losses on Financial Instruments Recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Investment loss	$ 1,971	$ 5,921
Financial instruments loss	3,165	6,946
Commodity price derivative loss
Derivative Instruments, Gain (Loss) [Line Items]
Derivative (loss) gain	(1,194)	(4,995)
Foreign currency derivatives gain
Derivative Instruments, Gain (Loss) [Line Items]
Derivative (loss) gain	$ 0	$ 3,970

Financial Instruments and Fai_5

Financial Instruments and Fair Value Measurement - Narrative (Details) $ in Millions	Mar. 31, 2019USD ($)
Carrying amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, fair value disclosure	$ 289.6
Value of the notes	112.4
Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, fair value disclosure	286.8
Value of the notes	$ 119
6.25% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	6.25%

Financial Instruments and Fai_6

Financial Instruments and Fair Value Measurement - Rollforward of Level 3 Financial Asset (Details) - Equity Securities - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance, investment - long-term	$ 8,711	$ 19,147
Transfer from long-term (Level 3) to current (Level 1)	0	(10,522)
Unrealized valuation (loss) gain	(417)	846
Unrealized foreign exchange gain (loss)	219	(760)
Closing balance, investment - long-term	$ 8,513	$ 8,711

Financial Instruments and Fai_7

Financial Instruments and Fair Value Measurement - Schedule of Commodity Price Derivative Positions and Commodity Foreign Currency Contracts (Details) - Commodity Hedge	3 Months Ended
	Mar. 31, 2019$ / bblbbl
Purchased Puts: April 1, to December 31, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (in barrels of oil per day) | bbl	5,000
Purchased Puts: April 1, to December 31, 2019 | Purchased | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in dollars per barrel)	60
Purchased Puts: April 1, to December 31, 2019 | Purchased | Call
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Premium Paid	2.39
Collars: April 1, to December 31, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (in barrels of oil per day) | bbl	5,000
Collars: April 1, to December 31, 2019 | Purchased | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in dollars per barrel)	60
Collars: April 1, to December 31, 2019 | Sold | Call
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor price (in dollars per barrel)	71.53

Financial Instruments and Fai_8

Financial Instruments and Fair Value Measurement - Schedule of Outstanding Foreign Currency Derivative Positions (Details) - Subsequent Event - Collars: May 1, to December 31, 2019 $ in Thousands, $ in Millions	May 07, 2019COP ($)$ / collar	May 07, 2019USD ($)$ / collar
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged	$ 180,000	$ 56,697
Purchased | Call
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cap Price (COP, Weighted Average)	3,446	3,446
Sold | Put
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Floor Price (COP, Weighted Average)	3,019	3,019

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information - Reconciliation of Cash, Cash Equivalents and Restricted Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Cash and cash equivalents	$ 32,740	$ 51,040	$ 160,474	$ 12,326
Restricted cash and cash equivalents - current	1,118	1,269	3,294	11,787
Restricted cash and cash equivalents - long-term (included in other long-term assets)	2,266	1,999	3,164	2,565
Cash, cash equivalents and restricted cash and cash equivalents	$ 36,124	$ 54,308	$ 166,932	$ 26,678

Supplemental Cash Flow Inform_4

Supplemental Cash Flow Information - Schedule of Net Changes in Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Accounts receivable and other long-term assets	$ (18,011)	$ (1,982)
Derivatives	(796)	1,847
Inventory	(1,749)	(1,785)
Prepaids	551	1,498
Accounts payable and accrued and other long-term liabilities	6,456	(2,495)
Taxes receivable and payable	(16,401)	(547)
Net changes in assets and liabilities from operating activities	$ (29,950)	$ (3,464)

Supplemental Cash Flow Inform_5

Supplemental Cash Flow Information - Schedule of Additional Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Net liabilities related to property, plant and equipment, end of period	$ 83,038	$ 70,108