Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES: The effective tax rates for the three months ended March 31, 2018 and 2017 were 28.8% and 34.3%, respectively. The effective tax rate for the three months ended March 31, 2018 differs from the U.S. federal statutory rate of 21% primarily due to state taxes and state valuation allowances. The effective rate for the three months ended March 31, 2017 differs from the U.S. federal statutory rate of 35% primarily due to state income taxes and equity compensation. On December 22, 2017, the United States enacted the Tax Cuts and Jobs Act (the "Act") which, among other things, lowered the U.S. Federal tax rate from 35% to 21%, repealed the corporate alternative minimum tax ("AMT"), and provided for a refunds of previously accrued AMT credits. The Company recorded a net tax benefit to reflect the impact of the Act as of December 31, 2017, as it is required to reflect the change in the period in which the law is enacted. Largely, the benefits recorded in the period ending December 31, 2017 related to tax reform are in recognition of the revaluation of deferred tax assets and liabilities, a benefit of $115,291, and a benefit for the reversal of a valuation allowance previously recorded against AMT credits which are now refundable, a benefit of $154,384. The net benefits for the Act as recorded as provisional amounts as of March 31, 2018 represent the Company's best estimate using information available to the Company as of May 3, 2018. The Company anticipates U.S. regulatory agencies will issue further regulations over the next year which may alter this estimate. The Company is still evaluating, among other things, the application of limitations for executive compensation related to contracts existing prior to November 2, 2017, and provisions in the Act addressing the deductibility of interest expense after January 1, 2018. The Company will refine its estimates to incorporate new or better information as it comes available through the filing date of its 2017 U.S. income tax returns in the fourth quarter of 2018. The total amount of uncertain tax positions at March 31, 2018 and December 31, 2017 was $37,813. If these uncertain tax positions were recognized, approximately $29,376 would affect CNX's effective tax rate at March 31, 2018 and December 31, 2017. There was no change to the unrecognized tax benefits during the three months ended March 31, 2018. CNX recognizes accrued interest related to uncertain tax positions in interest expense. As of March 31, 2018 and December 31, 2017, the Company reported an accrued interest liability relating to uncertain tax positions of $728 and $644, respectively, in Other Liabilities on the Consolidated Balance Sheets. The accrued interest liability includes $84 of accrued interest expense that is reflected in the Company's Consolidated Statements of Income for the three months ended March 31, 2018. CNX recognizes penalties accrued related to uncertain tax positions in its income tax expense. As of March 31, 2018 and December 31, 2017, CNX had no accrued liabilities for tax penalties related to uncertain tax positions. CNX and its subsidiaries file federal income tax returns with the United States and tax returns within various states and Canadian jurisdictions. With few exceptions, the Company is no longer subject to United States federal, state, local, or non-U.S. income tax examinations by tax authorities for the years before 2014. The Joint Committee on Taxation concluded its review of the audit of tax year 2015 on March 21, 2018. The audit resulted in a $108,651 reduction to CNX's net operating loss, primarily due to a reduction to the depreciation as an offset to the bonus depreciation taken in the 2010-2013 IRS audit. There was no cash impact from the audit.

INCOME TAXES:

The effective tax rates for the three months ended March 31, 2018 and 2017 were 28.8% and 34.3%, respectively. The effective tax rate for the three months ended March 31, 2018 differs from the U.S. federal statutory rate of 21% primarily due to state taxes and state valuation allowances. The effective rate for the three months ended March 31, 2017 differs from the U.S. federal statutory rate of 35% primarily due to state income taxes and equity compensation.

On December 22, 2017, the United States enacted the Tax Cuts and Jobs Act (the "Act") which, among other things, lowered the U.S. Federal tax rate from 35% to 21%, repealed the corporate alternative minimum tax ("AMT"), and provided for a refunds of previously accrued AMT credits. The Company recorded a net tax benefit to reflect the impact of the Act as of December 31, 2017, as it is required to reflect the change in the period in which the law is enacted. Largely, the benefits recorded in the period ending December 31, 2017 related to tax reform are in recognition of the revaluation of deferred tax assets and liabilities, a benefit of $115,291, and a benefit for the reversal of a valuation allowance previously recorded against AMT credits which are now refundable, a benefit of $154,384.

The net benefits for the Act as recorded as provisional amounts as of March 31, 2018 represent the Company's best estimate using information available to the Company as of May 3, 2018. The Company anticipates U.S. regulatory agencies will issue further regulations over the next year which may alter this estimate. The Company is still evaluating, among other things, the application of limitations for executive compensation related to contracts existing prior to November 2, 2017, and provisions in the Act addressing the deductibility of interest expense after January 1, 2018. The Company will refine its estimates to incorporate new or better information as it comes available through the filing date of its 2017 U.S. income tax returns in the fourth quarter of 2018.

The total amount of uncertain tax positions at March 31, 2018 and December 31, 2017 was $37,813. If these uncertain tax positions were recognized, approximately $29,376 would affect CNX's effective tax rate at March 31, 2018 and December 31, 2017. There was no change to the unrecognized tax benefits during the three months ended March 31, 2018.

CNX recognizes accrued interest related to uncertain tax positions in interest expense. As of March 31, 2018 and December 31, 2017, the Company reported an accrued interest liability relating to uncertain tax positions of $728 and $644, respectively, in Other Liabilities on the Consolidated Balance Sheets. The accrued interest liability includes $84 of accrued interest expense that is reflected in the Company's Consolidated Statements of Income for the three months ended March 31, 2018.

CNX recognizes penalties accrued related to uncertain tax positions in its income tax expense. As of March 31, 2018 and December 31, 2017, CNX had no accrued liabilities for tax penalties related to uncertain tax positions.

CNX and its subsidiaries file federal income tax returns with the United States and tax returns within various states and Canadian jurisdictions. With few exceptions, the Company is no longer subject to United States federal, state, local, or non-U.S. income tax examinations by tax authorities for the years before 2014. The Joint Committee on Taxation concluded its review of the audit of tax year 2015 on March 21, 2018. The audit resulted in a $108,651 reduction to CNX's net operating loss, primarily due to a reduction to the depreciation as an offset to the bonus depreciation taken in the 2010-2013 IRS audit. There was no cash impact from the audit.