Qep Resources (QEP) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2019shares
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	001-34778
Entity Registrant Name	QEP RESOURCES, INC.
Entity Incorporation, State or Country Code	DE
Entity Central Index Key	0001108827
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Tax Identification Number	87-0287750
Entity Address, Address Line One	1050 17th Street, Suite 800
Entity Address, City or Town	Denver
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80265
City Area Code	303
Local Phone Number	672-6900
Title of 12(b) Security	Common stock, $0.01 par value
Trading Symbol	QEP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	237,912,768

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues [Abstract]
Revenues	$ 296.2	$ 532.4	$ 576.8	$ 961.3
Operating Expenses [Abstract]
General and administrative	31.5	55.8	94.8	115.9
Production and property taxes	23.6	37.6	47.6	66.5
Depreciation, depletion and amortization	128	242.2	251.3	438.7
Exploration expenses	0	0.1	0	0.1
Impairment	0	403.7	5	404.4
Total Operating Expenses	241.7	850.3	524.9	1,261.3
Net gain (loss) from asset sales, inclusive of restructuring costs	17.8	(3.9)	4.6	(0.4)
OPERATING INCOME (LOSS)	72.3	(321.8)	56.5	(300.4)
Realized and unrealized gains (losses) on derivative contracts (Note 7)	38.5	(79.1)	(143.2)	(132.3)
Interest and other income (expense)	0.9	(3.1)	3.7	(3.8)
Interest expense	(33.2)	(38.2)	(67.2)	(73.2)
INCOME (LOSS) BEFORE INCOME TAXES	78.5	(442.2)	(150.2)	(509.7)
Income tax (provision) benefit	(29.7)	106.2	82.3	120.1
Net income (loss)	$ 48.8	$ (336)	$ (67.9)	$ (389.6)
Earnings Per Share [Abstract]
Basic	$ 0.20	$ (1.42)	$ (0.29)	$ (1.63)
Diluted	$ 0.20	$ (1.42)	$ (0.29)	$ (1.63)
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Used in basic calculation	238	237	237.5	238.9
Used in diluted calculation	238	237	237.5	238.9
Oil and Gas, Exploration and Production [Member]
Revenues [Abstract]
Revenues	$ 294.6	$ 520.3	$ 570.2	$ 930.1
Product and Service, Other [Member]
Revenues [Abstract]
Revenues	1.6	3	5.3	8
Oil and Gas, Purchased [Member]
Revenues [Abstract]
Revenues	0	9.1	1.3	23.2
Operating Expenses [Abstract]
Operating Costs and Expenses	0	9.8	1.4	25.3
Lease Operating Expense [Member]
Operating Expenses [Abstract]
Operating Costs and Expenses	45.7	66.5	97.2	139
Natural Gas, Gathering, Transportation, Marketing and Processing [Member]
Operating Expenses [Abstract]
Operating Costs and Expenses	9.9	31.2	20.8	65.2
Gathering and other expense [Member]
Operating Expenses [Abstract]
Operating Costs and Expenses	$ 3	$ 3.4	$ 6.8	$ 6.2

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019		Jun. 30, 2018		Jun. 30, 2019		Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 48.8		$ (336)		$ (67.9)		$ (389.6)
Fair value of plan assets adjustment(1)	0		0		0		0.3	[1]
Pension and other postretirement plans adjustments:
Amortization of prior service costs(2)	0		0.1	[2]	0.1		0.2	[2]
Amortization of actuarial losses(3)	0		0.2	[3]	0.1		0.4	[3]
Curtailment Gain (Loss), after Tax(4)	0.1	[4]	0		(0.3)	[4]	0
Other comprehensive income (loss)	0.1		0.3		(0.1)		0.9
Comprehensive income (loss)	$ 48.9		$ (335.7)		$ (68)		$ (388.7)
[1]	Adjustment recorded during the six months ended June 30, 2018 , related to a change in the fair value of plan assets as of December 31, 2017 .
[2]	Presented net of income tax expense of $0.1 million and $0.1 million for the three and six months ended June 30, 2018 , respectively.
[3]	Presented net of income tax expense of $0.1 million and $0.2 million for the three and six months ended June 30, 2018 , respectively.
[4]	Presented net of income tax expense of $0.1 million for the six months ended June 30, 2019 , respectively.

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018
Amortization of prior service cost, tax expense	[1]		$ 0.1			$ 0.1
Pension and other postretirement plans adjustments:
Amortization of net actuarial loss, income tax expense		$ 0	0.1	$ 0		0.2	[2]
Net curtailment (gain) loss, tax		$ 0	$ 0	$ (0.1)	[3]	$ 0
[1]	Presented net of income tax expense of $0.1 million and $0.1 million for the three and six months ended June 30, 2018 , respectively.
[2]	Presented net of income tax expense of $0.1 million and $0.2 million for the three and six months ended June 30, 2018 , respectively.
[3]	Presented net of income tax expense of $0.1 million for the six months ended June 30, 2019 , respectively.

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 97.1	$ 0
Accounts receivable, net	93.5	104.3
Income tax receivable	70.8	75.9
Fair value of derivative contracts	2.7	87.5
Prepaid expenses	7.1	12.7
Other current assets	0.2	0.2
Total Current Assets	271.4	280.6
Property, Plant and Equipment (successful efforts method for oil and gas properties)
Proved properties	9,316	9,096.9
Unproved properties	706.6	705.5
Gathering and other	169.1	167.7
Materials and supplies	20.9	29.9
Total Property, Plant and Equipment	10,212.6	10,000
Less Accumulated Depreciation, Depletion and Amortization
Exploration and production	5,050.9	4,882.4
Gathering and other	58.4	58.1
Total Accumulated Depreciation, Depletion and Amortization	5,109.3	4,940.5
Net Property, Plant and Equipment	5,103.3	5,059.5
Fair value of derivative contracts	15.2	35.4
Operating lease right-of-use assets, net	60.2	0
Other noncurrent assets	54.2	49.6
Noncurrent assets held for sale	0	692.7
TOTAL ASSETS	5,504.3	6,117.8
Current Liabilities
Checks outstanding in excess of cash balances	5.3	14.6
Accounts payable and accrued expenses	227.9	258.1
Production and property taxes	15.9	24.1
Current portion of long term debt	51.7	0
Interest payable	32.5	32.4
Fair value of derivative contracts	17.6	0
Current operating lease lease liabilities	18.8	0
Asset retirement obligations	6.8	5.1
Total Current Liabilities	376.5	334.3
Long-term debt	2,028.1	2,507.1
Deferred income taxes	181.4	269.2
Asset retirement obligations	94.6	96.9
Fair value of derivative contracts	0.9	0.7
Operating lease liabilities	47.9	0
Other long-term liabilities	85.6	97.4
Other long-term liabilities held for sale	0	61.3
Commitments and contingencies (Note 11)
EQUITY
Common stock – par value $0.01 per share; 500.0 million shares authorized; 242.0 million and 239.8 million shares issued, respectively	2.4	2.4
Treasury stock – 4.1 million and 3.1 million shares, respectively	(53.6)	(45.6)
Additional paid-in capital	1,446.3	1,431.9
Retained earnings	1,308.6	1,376.5
Accumulated other comprehensive income (loss)	(14.4)	(14.3)
Total Common Shareholders' Equity	2,689.3	2,750.9
TOTAL LIABILITIES AND EQUITY	$ 5,504.3	$ 6,117.8

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares shares in Millions	Jun. 30, 2019	Dec. 31, 2018
EQUITY
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	500	500
Common stock, shares issued (in shares)	242	239.8
Treasury stock (in shares)	4.1	3.1

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) Statement - USD ($) shares in Millions, $ in Millions	Total	Common Stock, Value [Member]	Stockholders' Equity, Total	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Other Comprehensive Income (Loss) [Member]	Total [Member]
Common Stock, Shares		243
Treasury Stock, Shares				(2)
Stockholders' Equity		$ 2.4		$ (34.2)	$ 1,398.2	$ 2,442.6	$ (11.1)	$ 3,797.9
Net income (loss)	$ (389.6)
Net income (loss), Shares		0		0
Net income (loss)	(389.6)	$ 0		$ 0	0	(389.6)	0	(389.6)
Common stock repurchased and retired, Shares		(6.2)		0
Common stock repurchased and retired	58.4	$ (0.1)	$ (58.4)	$ 0	0	(58.3)	0
Share-based compensation, Shares		2.9
Share-based compensation		$ 0.1
Stock Issued During Period, Shares, Treasury Stock Reissued				(0.7)
Share-based compensation				$ (7)	17.5	0	0	10.6
Stock Issued During Period, Shares, Employee Benefit Plan		0		0
Change in pension and postretirement liability, net of tax		$ 0		$ 0	0	0	0.9	0.9
Common Stock, Shares		240.3
Treasury Stock, Shares				(2.6)
Stockholders' Equity		$ 2.4		$ (39.5)	1,408	2,336.3	(10.5)	3,696.7
Net income (loss), Shares		0		0
Net income (loss)	$ (336)	$ 0		$ 0	0	(336)	0	(336)
Common stock repurchased and retired, Shares		(0.6)		0
Common stock repurchased and retired		$ 0	$ (5.6)	$ 0	0	(5.6)	0
Share-based compensation, Shares		0
Share-based compensation		$ 0
Stock Issued During Period, Shares, Treasury Stock Reissued				(0.1)
Share-based compensation				$ (1.7)	7.7	0	0	6
Stock Issued During Period, Shares, Employee Benefit Plan		0		0
Change in pension and postretirement liability, net of tax		$ 0		$ 0	0	0	0.3	0.3
Common Stock, Shares		239.7
Treasury Stock, Shares				(2.7)
Stockholders' Equity		$ 2.4		$ (41.2)	1,415.7	1,994.7	(10.2)	3,361.4
Common Stock, Shares		239.8
Treasury Stock, Shares	(3.1)			(3.1)
Stockholders' Equity	$ 2,750.9	$ 2.4		$ (45.6)	1,431.9	1,376.5	(14.3)	2,750.9
Net income (loss), Shares		0		0
Net income (loss)	(67.9)	$ 0		$ 0	0	(67.9)	0	(67.9)
Common stock repurchased and retired	0
Share-based compensation, Shares		2.2
Share-based compensation		$ 0
Stock Issued During Period, Shares, Treasury Stock Reissued				(1)
Share-based compensation				$ (8)	14.4	0	0	6.4
Stock Issued During Period, Shares, Employee Benefit Plan		0		0
Change in pension and postretirement liability, net of tax		$ 0		$ 0	0	0	(0.1)	(0.1)
Common Stock, Shares		242
Treasury Stock, Shares				(3.9)
Stockholders' Equity		$ 2.4		$ (51.8)	1,440.2	1,259.8	(14.5)	2,636.1
Net income (loss), Shares		0		0
Net income (loss)	$ 48.8	$ 0		$ 0	0	48.8	0	48.8
Share-based compensation, Shares		0
Share-based compensation		$ 0
Stock Issued During Period, Shares, Treasury Stock Reissued				(0.2)
Share-based compensation				$ (1.8)	6.1	0	0	4.3
Stock Issued During Period, Shares, Employee Benefit Plan		0		0
Change in pension and postretirement liability, net of tax		$ 0		$ 0	0	0	0.1	0.1
Common Stock, Shares		242
Treasury Stock, Shares	(4.1)			(4.1)
Stockholders' Equity	$ 2,689.3	$ 2.4		$ (53.6)	$ 1,446.3	$ 1,308.6	$ (14.4)	$ 2,689.3

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES
Net income (loss)	$ (67.9)	$ (389.6)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	251.3	438.7
Deferred income taxes (benefit)	(87.7)	(120.5)
Impairment	5	404.4
Non-cash share-based compensation	11.2	16.3
Amortization of debt issuance costs and discounts	2.7	2.6
Net (gain) loss from asset sales, inclusive of restructuring costs	(4.6)	0.4
Unrealized (gains) losses on marketable securities	(2.7)	(0.4)
Unrealized (gains) losses on derivative contracts	121.3	43.6
Changes in operating assets and liabilities	(32.9)	(18.6)
Net Cash Provided by (Used in) Operating Activities	195.7	376.9
INVESTING ACTIVITIES
Property acquisitions	(1.8)	(45.1)
Property, plant and equipment, including exploratory well expense	(316.8)	(764.3)
Proceeds from disposition of assets	666.7	48.8
Net Cash Provided by (Used in) Investing Activities	348.1	(760.6)
FINANCING ACTIVITIES
Checks outstanding in excess of cash balances	(9.3)	(35.5)
Proceeds from credit facility	56	2,029.5
Repayments of credit facility	(486)	(1,543.5)
Common stock repurchased and retired	0	(58.4)
Treasury stock repurchases	(6.3)	(5.9)
Other capital contributions	0	0.2
Net Cash Provided by (Used in) Financing Activities	(445.6)	386.4
Change in cash, cash equivalents and restricted cash(1)	98.2	2.7
Beginning cash, cash equivalents and restricted cash(1)	28.1	23.4
Ending cash, cash equivalents and restricted cash(1)	126.3	26.1
Supplemental Disclosures:
Cash paid for interest, net of capitalized interest	63.3	63.5
Cash paid for income taxes, net	1.5	0.2
Cash Paid for Amounts Included in the Measurement of Lease Liabilities	13.1	0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	9.8	0
Non-cash Investing Activities:
Change in capital expenditure accruals and other non-cash adjustments	$ 20.3	$ 20.2

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation [Text Block]	Nature of Business QEP Resources, Inc. (QEP or the Company) is an independent crude oil and natural gas exploration and production company with operations in two regions of the United States: the Southern Region (primarily in Texas) and the Northern Region (primarily in North Dakota). Unless otherwise specified or the context otherwise requires, all references to "QEP" or the "Company" are to QEP Resources, Inc. and its subsidiaries on a consolidated basis. QEP's corporate headquarters are located in Denver, Colorado and shares of QEP's common stock trade on the New York Stock Exchange (NYSE) under the ticker symbol "QEP". Basis of Presentation of Interim Condensed Consolidated Financial Statements The interim Condensed Consolidated Financial Statements contain the accounts of QEP and its majority-owned or controlled subsidiaries. The Condensed Consolidated Financial Statements were prepared in accordance with Generally Accepted Accounting Principles (GAAP) in the United States and with the instructions for Quarterly Reports on Form 10-Q and Regulation S-X. All significant intercompany accounts and transactions have been eliminated in consolidation. The Condensed Consolidated Financial Statements reflect all normal recurring adjustments and accruals that are, in the opinion of management, necessary for a fair statement of financial position and results of operations for the interim periods presented. Interim Condensed Consolidated Financial Statements and the year-end balance sheet do not include all of the information and notes required by GAAP for audited annual consolidated financial statements. These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 . The preparation of the Condensed Consolidated Financial Statements and Notes in conformity with GAAP requires that management make estimates and assumptions that affect revenues, expenses, assets and liabilities, and disclosure of contingent assets and liabilities. Actual results could differ from estimates. The results of operations for the three and six months ended June 30, 2019 , are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . Reclassifications Certain prior period balances on the Condensed Consolidated Statements of Cash Flows have been reclassified to conform to the current year presentation. Such reclassifications had no effect on the Company's net income (loss), earnings (loss) per share or retained earnings previously reported. Impairment of Long-Lived Assets During the six months ended June 30, 2019 , QEP recorded impairment charges of $5.0 million related to an office building lease. During the six months ended June 30, 2018 , QEP recorded impairment charges of $404.4 million , of which $402.8 million of proved and unproved properties impairment was triggered due to the signing of a purchase and sale agreement for the divestiture of the Uinta Basin assets. Additionally, QEP recorded $1.6 million related to expiring leaseholds on unproved properties and impairment of proved properties for a divestiture in the Other Northern area. Cash, Cash Equivalents and Restricted Cash Cash equivalents consist principally of highly liquid investments in securities with original maturities of three months or less made through commercial bank accounts that result in available funds the next business day. Restricted cash are funds that are legally or contractually reserved for a specific purpose and therefore not available for immediate or general business use. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Condensed Consolidated Balance Sheets to the amounts shown in the Condensed Consolidated Statements of Cash Flows: June 30, 2019 2018 (in millions) Cash and cash equivalents $ 97.1 $ — Restricted cash (1) 29.2 26.1 Total cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 126.3 $ 26.1 _______________________ (1) As of June 30, 2019 and 2018 , the restricted cash balance is cash held in an escrow account related to a title dispute between outside parties in the Williston Basin, and the restricted cash balance is recorded within "Other noncurrent assets" on the Condensed Consolidated Balance Sheets. New Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842), which requires lessees to recognize the lease assets and lease liabilities classified as operating leases on the balance sheet and disclose key quantitative and qualitative information about leasing arrangements. The FASB subsequently issued various ASUs which provided additional implementation guidance. The Company adopted ASU 2016-02 on January 1, 2019 using the modified retrospective approach and elected to not adjust periods prior to January 1, 2019. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which, among other things, allowed the carry forward of the historical lease classification, including accounting treatment for land easements. This standard does not apply to QEP's leases that provide the right to explore for minerals, oil or natural gas resources. The adoption of this guidance resulted in the recognition of net operating lease right-of-use assets and operating lease liabilities on QEP's Condensed Consolidated Balance Sheets. These leases primarily relate to office buildings, compressors and generators. This guidance did not have a significant impact on the Condensed Consolidated Statement of Operations or the Condensed Consolidated Statement of Cash Flows. Refer to Note 8 – Leases for more information.

Revenue Revenue

Revenue Revenue	6 Months Ended
	Jun. 30, 2019
Revenue Recognition [Abstract]
Revenue	Revenue Recognition QEP recognizes revenue from the sale of oil and condensate, gas and NGL in the period that the performance obligations are satisfied. QEP's performance obligations are satisfied when the customer obtains control of product, when QEP has no further obligations to perform related to the sale, when the transaction price has been determined and when collectability is probable. The sale of oil and condensate, gas and NGL are made under contracts with customers, which typically include consideration that is based on pricing tied to local indices and volumes delivered in the current month. Reported revenues include estimates for the two most recent months using published commodity price indices and volumes supplied by field operators. Performance obligations under our contracts with customers are typically satisfied at a point in time through monthly delivery of oil and condensate, gas and/or NGL. Our contracts with customers typically require payment for oil and condensate, gas and NGL sales within 30 days following the calendar month of delivery. QEP's oil is typically sold at specific delivery points under contract terms that are common in the industry. QEP's gas and NGL are also sold under contract types that are common in the industry; however, under these contracts, the gas and its components, including NGL, may be sold to a single purchaser or the residue gas and NGL may be sold to separate purchasers. Regardless of the contract type, the terms of these contracts compensate QEP for the value of the residue gas and NGL constituent components at market prices for each product. QEP also purchases and resells oil and gas primarily to mitigate credit risk related to third party purchasers, to fulfill volume commitments when production does not fulfill contractual commitments and to capture additional margin from subsequent sales of third party purchases. QEP recognizes revenue from these resale activities in the period that the performance obligations are satisfied. The following tables present QEP's revenues that are disaggregated by revenue source and by geographic area. Transportation and processing costs in the following table are not all of the transportation and processing costs that QEP incurs, only the expenses that are netted against revenues pursuant to ASC Topic 606. Oil and condensate sales Gas sales NGL sales Transportation and processing costs included in revenue Oil and condensate, gas and NGL sales, as reported (in millions) Three Months Ended June 30, 2019 Northern Region Williston Basin $ 107.5 $ 7.5 $ 5.8 $ (8.9 ) $ 111.9 Other Northern 0.5 0.1 — — 0.6 Southern Region Permian Basin 177.6 (0.6 ) 8.5 (3.8 ) 181.7 Other Southern 0.1 0.3 — — 0.4 Total oil and condensate, gas and NGL sales $ 285.7 $ 7.3 $ 14.3 $ (12.7 ) $ 294.6 Three Months Ended June 30, 2018 Northern Region Williston Basin $ 207.6 $ 8.4 $ 14.7 $ (10.7 ) $ 220.0 Uinta Basin 9.5 7.9 1.7 — 19.1 Other Northern 0.9 0.2 0.1 — 1.2 Southern Region Permian Basin 190.3 3.2 9.9 (1.7 ) 201.7 Haynesville/Cotton Valley 0.2 77.9 — — 78.1 Other Southern — 0.2 — — 0.2 Total oil and condensate, gas and NGL sales $ 408.5 $ 97.8 $ 26.4 $ (12.4 ) $ 520.3 Oil and condensate sales Gas sales NGL sales Transportation and processing costs included in revenue Oil and condensate, gas and NGL sales, as reported (in millions) Six Months Ended June 30, 2019 Northern Region Williston Basin $ 217.4 $ 20.0 $ 13.2 $ (19.0 ) $ 231.6 Other Northern 0.9 0.3 — — 1.2 Southern Region Permian Basin 316.8 4.0 18.0 (7.5 ) 331.3 Other Southern 0.1 6.0 — — 6.1 Total oil and condensate, gas and NGL sales $ 535.2 $ 30.3 $ 31.2 $ (26.5 ) $ 570.2 Six Months Ended June 30, 2018 Northern Region Williston Basin $ 368.1 $ 18.2 $ 26.5 $ (20.6 ) $ 392.2 Uinta Basin 17.9 18.0 3.4 — 39.3 Other Northern 2.8 1.2 (0.1 ) — 3.9 Southern Region Permian Basin 320.1 7.8 16.4 (4.5 ) 339.8 Haynesville/Cotton Valley 0.6 154.3 — — 154.9 Other Southern (0.3 ) 0.3 — — — Total oil and condensate, gas and NGL sales $ 709.2 $ 199.8 $ 46.2 $ (25.1 ) $ 930.1

Acquisitions & Divestitures

Acquisitions & Divestitures	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Acquisitions & Divestitures [Text Block]	Acquisitions During the six months ended June 30, 2019 , QEP acquired various oil and gas properties, which primarily included proved leasehold acreage in the Permian Basin for an aggregate purchase price of $1.8 million , subject to post-closing purchase price adjustments. During the six months ended June 30, 2018 , QEP acquired various oil and gas properties, which primarily included proved and unproved leasehold acreage in the Permian Basin for an aggregate purchase price of $45.1 million . Of the $45.1 million , $37.5 million was related to acquisitions from various entities that owned additional oil and gas interests in certain properties included in the 2017 acquisition of oil and gas properties in the Permian Basin (the 2017 Permian Basin Acquisition) on substantially the same terms and conditions as the 2017 Permian Basin Acquisition. Divestitures In February 2018, QEP's Board of Directors unanimously approved certain strategic and financial initiatives including plans to market its assets in the Williston Basin, the Uinta Basin and Haynesville/Cotton Valley and focus its activities in the Permian Basin. The Company subsequently closed the sale of its Uinta Basin assets in the third quarter of 2018 and the sale of the Haynesville/Cotton Valley assets in the first quarter of 2019 . In November 2018, the Company's wholly owned subsidiary, QEP Energy Company, entered into a purchase and sale agreement for its assets in the Williston Basin, however, in February 2019, the Company agreed with the buyer to terminate the purchase and sale agreement. Haynesville/Cotton Valley Divestiture In January 2019, QEP closed the sale of its assets in Haynesville/Cotton Valley (Haynesville Divestiture), and in July 2019 QEP reached final settlement on asserted title defects. The purchase price, after adjustments, is $634.2 million . QEP received net cash proceeds of $627.1 million during the six months ended June 30, 2019 , and, as of June 30, 2019 , recorded a $9.5 million receivable and a $2.4 million payable which were included in "Accounts receivable, net" and "Accounts payable and accrued expenses", respectively. The total pre-tax loss on sale was $3.7 million , of which $0.7 million was recognized during the six months ended June 30, 2019 , within "Net gain (loss) from asset sales, inclusive of restructuring costs" on the Condensed Consolidated Statements of Operations. Included in the $0.7 million pre-tax loss on sale is $1.4 million of restructuring costs related to the Haynesville Divestiture. Refer to Note 9 – Restructuring for more information. As of December 31, 2018, it was deemed unlikely that there will be any significant changes to the Haynesville Divestiture. Accordingly, the assets and liabilities associated with the Haynesville Divestiture were classified as noncurrent assets and liabilities held for sale, on the Condensed Consolidated Balance Sheets. During the six months ended June 30, 2019 , QEP accounted for revenues and expenses related to Haynesville/Cotton Valley, including the pre-tax loss on sale of $0.7 million , as income from continuing operations on the Condensed Consolidated Statements of Operations because the Haynesville Divestiture did not cause a strategic shift for the Company and therefore did not qualify as discontinued operations under ASU 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity . During the three months ended June 30, 2019 , QEP recorded net income before income taxes related to the divested Haynesville/Cotton Valley properties of $14.4 million , which includes a pre-tax gain on sale of $14.3 million . During the six months ended June 30, 2019 , QEP recorded net income before income taxes related to the divested Haynesville/Cotton Valley properties of $3.3 million , which includes the pre-tax loss on sale of $0.7 million . For the three and six months ended June 30, 2018 , QEP recorded net income before income taxes related to the divested Haynesville/Cotton Valley properties of $7.4 million and $19.7 million , respectively. The following table presents the carrying amounts of the major classes of assets and liabilities related to the Haynesville Divestiture classified as noncurrent assets and liabilities held for sale on the Condensed Consolidated Balance Sheets: December 31, 2018 (1) (in millions) Assets Current assets, total $ 1.2 Net Property, Plant and Equipment 683.7 Other noncurrent assets 7.8 Noncurrent assets held for sale $ 692.7 Liabilities Current liabilities, total $ 3.4 Asset retirement obligations, current 0.7 Asset retirement obligations, long-term 56.9 Other long-term liabilities 0.3 Other long-term liabilities held for sale $ 61.3 ____________________________ (1) The Haynesville Divestiture closed in January 2019, therefore there are no assets and liabilities held for sale as of June 30, 2019 . Uinta Basin Divestiture In September 2018, QEP sold its natural gas and oil producing properties, undeveloped acreage and related assets located in the Uinta Basin for net cash proceeds of $153.0 million (Uinta Basin Divestiture). During the three and six months ended June 30, 2019 , QEP recorded a pre-tax loss on sale of $0.3 million and $0.2 million , respectively, due to post-closing purchase price adjustments, which were recorded within "Net gain (loss) from asset sales, inclusive of restructuring costs". For the three and six months ended June 30, 2018 , QEP recorded a net loss before income taxes related to the divested Uinta Basin assets of $409.9 million and $414.9 million , respectively. The net loss before income taxes was primarily due to an impairment charge on proved and unproved properties of $402.8 million recognized as a result of signing the purchase and sale agreement. Pinedale Divestiture In September 2017, QEP sold its Pinedale assets (Pinedale Divestiture) for net cash proceeds (after purchase price adjustments) of $718.2 million . During the six months ended June 30, 2018 , QEP recorded a pre-tax gain on sale of $0.8 million , due to post-closing purchase price adjustments, which were recorded within "Net gain (loss) from asset sales, inclusive of restructuring costs". QEP agreed to reimburse the buyer of its Pinedale assets for certain deficiency charges it incurs related to gas processing and NGL transportation and fractionation contracts, if any, between the effective date of the sale and December 31, 2019, in an aggregate amount not to exceed $45.0 million . As of June 30, 2019 , the remaining liability associated with estimated future payments for this commitment was $2.0 million and is reported on the Condensed Consolidated Balance Sheets within "Accounts payable and accrued expenses". Other Divestitures During the six months ended June 30, 2019 , QEP received net cash proceeds of $39.7 million and recorded a net pre-tax gain on sale of $5.5 million related to the divestiture of properties outside its main operating areas. During the six months ended June 30, 2018 , QEP received net cash proceeds of $48.8 million and recorded a pre-tax gain on sale of $0.7 million , primarily related to the divestiture of properties outside its main operating areas in the Uinta Basin, Pinedale and Other Northern area, and the sale of an underground gas storage facility. These gains and losses were recorded within "Net gain (loss) from asset sales, inclusive of restructuring costs" on the Condensed Consolidated Statements of Operations.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Basic earnings (loss) per share (EPS) are computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the reporting period. Diluted EPS includes the potential increase in the number of outstanding shares that could result from the exercise of in-the-money stock options. QEP's unvested restricted share awards are included in weighted-average basic common shares outstanding because, once the shares are granted, the restricted share awards are considered issued and outstanding, the historical forfeiture rate is minimal and the restricted share awards are eligible to receive dividends. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents are considered participating securities and are included in the computation of earnings (loss) per share pursuant to the two-class method. The Company's unvested restricted share awards contain non-forfeitable dividend rights and participate equally with common stock with respect to dividends issued or declared. However, the Company's unvested restricted share awards do not have a contractual obligation to share in losses of the Company. The Company's unexercised stock options do not contain rights to dividends. Under the two-class method, the earnings used to determine basic earnings (loss) per common share are reduced by an amount allocated to participating securities. When the Company records a net loss, none of the loss is allocated to the participating securities since the securities are not obligated to share in Company losses. Use of the two-class method has an insignificant impact on the calculation of basic and diluted earnings (loss) per common share. During the three and six months ended June 30, 2019 there were no anti-dilutive shares. During the three and six months ended June 30, 2018 , 0.1 million shares were not included in diluted common shares outstanding as they were anti-dilutive to QEP's net loss. The following is a reconciliation of the components of basic and diluted shares used in the EPS calculation: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 (in millions) Weighted-average basic common shares outstanding 238.0 237.0 237.5 238.9 Potential number of shares issuable upon exercise of in-the-money stock options under the Long-Term Stock Incentive Plan — — — — Average diluted common shares outstanding 238.0 237.0 237.5 238.9

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2019
Asset Retirement Obligation [Abstract]
Asset Retirement Obligations [Text Block]	QEP records asset retirement obligations (ARO) associated with the retirement of tangible, long-lived assets. The Company's ARO liability applies primarily to abandonment costs associated with oil and gas wells and certain other properties. The fair values of such costs are estimated by Company personnel based on abandonment costs of similar assets and depreciated over the life of the related assets. Revisions to the ARO estimates result from changes in expected cash flows or material changes in estimated asset retirement costs. The ARO liability is adjusted to present value each period through an accretion calculation using a credit-adjusted risk-free interest rate. The Condensed Consolidated Balance Sheet line items of QEP's ARO liability are presented in the table below: Asset Retirement Obligations June 30, December 31, 2019 2018 Balance Sheet line item (in millions) Current: Asset retirement obligations, current liability $ 6.8 $ 5.1 Long-term: Asset retirement obligations 94.6 96.9 Other long-term liabilities held for sale — 57.6 Total ARO Liability $ 101.4 $ 159.6 The following is a reconciliation of the changes in the Company's ARO for the period specified below: Asset Retirement Obligations (in millions) ARO liability at January 1, 2019 $ 159.6 Accretion 3.1 Additions 0.4 Revisions (0.3 ) Liabilities related to assets sold (1) (60.7 ) Liabilities settled (0.7 ) ARO liability at June 30, 2019 $ 101.4 _______________________ (1) Liabilities related to assets sold during the six months ended June 30, 2019 , includes $57.6 million related to the Haynesville Divestiture (refer to Note 3 – Acquisitions and Divestitures for more information).

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements [Text Block]	QEP measures and discloses fair values in accordance with the provisions of ASC 820, Fair Value Measurements and Disclosures . This guidance defines fair value in applying GAAP, establishes a framework for measuring fair value and expands disclosures about fair value measurements. ASC 820 also establishes a fair value hierarchy. Level 1 inputs are quoted prices (unadjusted) for identical assets or liabilities in active markets that the Company has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3 inputs are unobservable inputs for the asset or liability. QEP has determined that its commodity derivative instruments are Level 2. The Level 2 fair value of commodity derivative contracts (refer to Note 7 – Derivative Contracts for more information) is based on market prices posted on the respective commodity exchange on the last trading day of the reporting period and industry standard discounted cash flow models. QEP primarily applies the market approach for recurring fair value measurements and maximizes its use of observable inputs and minimizes its use of unobservable inputs. QEP considers bid and ask prices for valuing the majority of its assets and liabilities measured and reported at fair value. In addition to using market data, QEP makes assumptions in valuing its assets and liabilities, including assumptions about risk and the risks inherent in the inputs to the valuation technique. The Company's policy is to recognize significant transfers between levels at the end of the reporting period. Certain of the Company's commodity derivative instruments are valued using industry standard models that consider various inputs, including quoted forward prices for commodities, time value, volatility, and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these inputs are observable in the marketplace throughout the full term of the instrument and can be derived from observable data or are supported by observable prices at which transactions are executed in the marketplace. The determination of fair value for derivative assets and liabilities also incorporates nonperformance risk for counterparties and for QEP. Derivative contract fair values are reported on a net basis to the extent a legal right of offset with the counterparty exists. The fair value of financial assets and liabilities at June 30, 2019 and December 31, 2018 , is shown in the table below: Fair Value Measurements Gross Amounts of Assets and Liabilities Netting Adjustments (1) Net Amounts Presented on the Condensed Consolidated Balance Sheets Level 1 Level 2 Level 3 (in millions) Financial Assets June 30, 2019 Fair value of derivative contracts – short-term $ — $ 2.7 $ — $ — $ 2.7 Fair value of derivative contracts – long-term — 15.2 — — 15.2 Total financial assets $ — $ 17.9 $ — $ — $ 17.9 Financial Liabilities Fair value of derivative contracts – short-term $ — $ 17.6 $ — $ — $ 17.6 Fair value of derivative contracts – long-term — 0.9 — — 0.9 Total financial liabilities $ — $ 18.5 $ — $ — $ 18.5 December 31, 2018 Financial Assets Fair value of derivative contracts – short-term (2) $ — $ 88.2 $ — $ (0.4 ) $ 87.8 Fair value of derivative contracts – long-term — 35.4 — — 35.4 Total financial assets $ — $ 123.6 $ — $ (0.4 ) $ 123.2 Financial Liabilities Fair value of derivative contracts – short-term $ — $ 0.4 $ — $ (0.4 ) $ — Fair value of derivative contracts – long-term — 0.7 — — 0.7 Total financial liabilities $ — $ 1.1 $ — $ (0.4 ) $ 0.7 _______________________ (1) The Company nets its derivative contract assets and liabilities outstanding with the same counterparty on the Condensed Consolidated Balance Sheets for the contracts that contain netting provisions. Refer to Note 7 – Derivative Contracts for additional information regarding the Company's derivative contracts. (2) Includes fair value of derivative contracts classified as "Noncurrent assets held for sale" of $0.3 million as of December 31, 2018 on the Condensed Consolidated Balance Sheets related to the Haynesville Divestiture. The following table discloses the fair value and related carrying amount of certain financial instruments not disclosed in other Notes to the Condensed Consolidated Financial Statements in this Quarterly Report on Form 10-Q: Carrying Amount Level 1 Fair Value Carrying Amount Level 1 Fair Value June 30, 2019 December 31, 2018 Financial Assets (in millions) Cash and cash equivalents $ 97.1 $ 97.1 $ — $ — Financial Liabilities Checks outstanding in excess of cash balances $ 5.3 $ 5.3 $ 14.6 $ 14.6 Total debt outstanding $ 2,079.8 $ 2,042.5 $ 2,507.1 $ 2,350.5 The carrying amounts of cash and cash equivalents and checks outstanding in excess of cash balances approximate fair value. The fair value of fixed-rate long-term debt is based on the trading levels and dollar prices for the Company's debt at the end of the quarter. The carrying amount of variable-rate long-term debt approximates fair value because the floating interest rate paid on such debt was set for periods of one month. The fair value of the deficiency charge obligation associated with the Pinedale Divestiture was measured utilizing an internally developed cash flow model discounted at QEP's weighted average cost of debt. Given the unobservable nature of the inputs, the fair value calculation associated with the deficiency charges is considered Level 3 within the fair value hierarchy . Refer to Note 3 – Acquisitions and Divestitures for more information. The initial measurement of ARO at fair value is calculated using discounted cash flow techniques and is based on internal estimates of future retirement costs associated with property, plant and equipment. Significant Level 3 inputs used in the calculation of ARO includes plugging costs and reserve lives. A reconciliation of the Company's ARO is presented in Note 5 – Asset Retirement Obligations . Nonrecurring Fair Value Measurements The provisions of the fair value measurement standard are also applied to the Company's nonrecurring measurements. The Company utilizes fair value on a periodic basis, at least annually, to review its proved oil and gas properties and operating lease right-of-use assets for potential impairment when events and changes in circumstances indicate that the carrying amount of such property may not be recoverable. The fair value of property is measured utilizing the income approach and utilizing inputs that are primarily based upon internally developed cash flow models discounted at an appropriate weighted average cost of capital. In addition, the signing of a purchase and sale agreement could also trigger an impairment of proved properties. For assets subject to a purchase and sale agreement, the terms of the purchase and sale agreement are used as an indicator of fair value. If a range is estimated for the amount of future cash flows, the fair value of property is measured utilizing a probability-weighted approach in which the likelihood of possible outcomes is taken into consideration. Given the unobservable nature of the inputs, fair value calculations associated with long-term operating lease right-of-use assets and proved oil and gas property impairments are considered Level 3 within the fair value hierarchy. During the six months ended June 30, 2019 , the Company recorded impairment charges of $5.0 million related to an office building lease. During the six months ended June 30, 2018 , the Company recorded impairments on certain proved oil and gas properties of $397.6 million . Acquisitions of proved and unproved properties are also measured at fair value on a nonrecurring basis. The Company utilizes a discounted cash flow model to estimate the fair value of acquired property as of the acquisition date, which utilizes the following inputs to estimate future net cash flows: (i) estimated quantities of oil and condensate, gas and NGL reserves; (ii) estimates of future commodity prices; and (iii) estimated production rates, and future operating and development costs, which are based on the Company's historic experience with similar properties. In some instances, market comparable information of recent transactions is used to estimate fair value of unproved acreage. Due to the unobservable characteristics of the inputs, the fair value of the acquired properties is considered Level 3 within the fair value hierarchy. Refer to Note 3 – Acquisitions and Divestitures for more information on the fair value of acquired properties.

Derivative Contracts

Derivative Contracts	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	QEP has established policies and procedures for managing commodity price volatility through the use of derivative instruments. In the normal course of business, QEP uses commodity price derivative instruments to reduce the impact of potential downward movements in commodity prices on cash flow, returns on capital investment, and other financial results. However, these instruments typically limit gains from favorable price movements. The volume of production subject to commodity derivative instruments and the mix of the instruments are frequently evaluated and adjusted by management in response to changing market conditions. QEP may enter into commodity derivative contracts for up to 100% of forecasted production, but generally, QEP enters into commodity derivative contracts for approximately 50% to 75% of its forecasted annual production by the end of the first quarter of each fiscal year. In addition, during the time that QEP owned gas storage facilities or had contracts for gas storage capacity, QEP entered into commodity derivative contracts on a portion of its storage transactions. QEP does not enter into commodity derivative contracts for speculative purposes. QEP uses commodity derivative instruments known as fixed-price swaps or costless collars to realize a known price or price range for a specific volume of production delivered into a regional sales point. QEP's commodity derivative instruments do not require the physical delivery of oil or gas between the parties at settlement. All transactions are settled in cash with one party paying the other for the net difference in prices, multiplied by the contract volume, for the settlement period. Oil price derivative instruments are typically structured as NYMEX fixed-price swaps based at Cushing, Oklahoma. Gas price derivative instruments are typically structured as fixed-price swaps or collars at NYMEX Henry Hub or regional price indices. QEP also enters into oil basis swaps to achieve a fixed-price swap for a portion of its oil sales at prices that reference specific regional index prices. QEP does not currently have any commodity derivative instruments that have margin requirements or collateral provisions that would require payments prior to the scheduled settlement dates. QEP's commodity derivative contract counterparties are typically financial institutions and energy trading firms with investment-grade credit ratings. QEP routinely monitors and manages its exposure to counterparty risk by requiring specific minimum credit standards for all counterparties, actively monitoring counterparties' public credit ratings and avoiding the concentration of credit exposure by transacting with multiple counterparties. The Company has master-netting agreements with some counterparties that allow the offsetting of receivables and payables in a default situation. Derivative Contracts – Production The following table presents QEP's volumes and average prices for its commodity derivative swap contracts as of June 30, 2019 : Year Index Total Volumes Average Swap Price per Unit (in millions) Oil sales (bbls) ($/bbl) 2019 NYMEX WTI 6.6 $ 55.24 2019 ICE Brent 0.9 $ 66.73 2019 Argus WTI Houston 0.2 $ 65.70 2020 NYMEX WTI 6.2 $ 60.07 2020 Argus WTI Midland 0.7 $ 60.00 QEP uses oil basis swaps, combined with NYMEX WTI fixed-price swaps, to achieve fixed price swaps for the location at which it sells its physical production. The following table presents details of QEP's oil basis swaps as of June 30, 2019 : Year Index Basis Total Volumes Weighted-Average Differential (in millions) Oil sales (bbls) ($/bbl) 2019 NYMEX WTI Argus WTI Midland 3.3 $ (2.22 ) 2019 NYMEX WTI Argus WTI Houston 0.9 $ 3.69 2020 NYMEX WTI Argus WTI Midland 4.4 $ (0.02 ) 2020 (January - June) NYMEX WTI Argus WTI Houston 0.4 $ 3.75 QEP Derivative Financial Statement Presentation The following table identifies the Condensed Consolidated Balance Sheet location of QEP's outstanding derivative contracts on a gross contract basis as opposed to the net contract basis presentation on the Condensed Consolidated Balance Sheets and the related fair values at the balance sheet dates: Gross asset derivative Gross liability derivative Balance Sheet line item June 30, December 31, June 30, December 31, Current: (in millions) Commodity (1) Fair value of derivative contracts $ 2.7 $ 88.2 $ 17.6 $ 0.4 Long-term: Commodity Fair value of derivative contracts 15.2 35.4 0.9 0.7 Total derivative instruments $ 17.9 $ 123.6 $ 18.5 $ 1.1 _______________________ (1) Includes fair value of derivative contracts classified as "Noncurrent assets held for sale" of $0.3 million as of December 31, 2018 on the Condensed Consolidated Balance Sheet related to the Haynesville Divestiture. The effects of the change in fair value and settlement of QEP's derivative contracts recorded in "Realized and unrealized gains (losses) on derivative contracts" on the Condensed Consolidated Statements of Operations are summarized in the following table: Three Months Ended Six Months Ended Derivative contracts June 30, June 30, 2019 2018 2019 2018 Realized gains (losses) on commodity derivative contracts (in millions) Production Oil derivative contracts $ (16.0 ) $ (52.0 ) $ (19.0 ) $ (96.3 ) Gas derivative contracts — 6.4 (2.9 ) 7.3 Gas Storage Gas derivative contracts — 0.1 — 0.3 Realized gains (losses) on commodity derivative contracts (16.0 ) (45.5 ) (21.9 ) (88.7 ) Unrealized gains (losses) on commodity derivative contracts Production Oil derivative contracts 54.5 (20.6 ) (122.8 ) (27.5 ) Gas derivative contracts — (13.0 ) (0.3 ) (15.8 ) Gas Storage Gas derivative contracts — — — (0.3 ) Unrealized gains (losses) on commodity derivative contracts 54.5 (33.6 ) (123.1 ) (43.6 ) Total realized and unrealized gains (losses) on commodity derivative contracts related to production and storage $ 38.5 $ (79.1 ) $ (145.0 ) $ (132.3 ) Derivatives associated with Haynesville Divestiture Unrealized gains (losses) on commodity derivative contracts Production Gas derivative contracts — — 1.8 — Unrealized gains (losses) on commodity derivative contracts related to divestitures (1) $ — $ — $ 1.8 $ — Total realized and unrealized gains (losses) on commodity derivative contracts $ 38.5 $ (79.1 ) $ (143.2 ) $ (132.3 ) _______________________ (1) During the three and six months ended June 30, 2019 , the unrealized gains (losses) on commodity derivative contracts related to the Haynesville Divestiture were comprised of derivatives included as part of the Haynesville/Cotton Valley purchase and sale agreement, which were subsequently novated to the buyer upon the closing of the sale in January 2019. Refer to Note 3 – Acquisitions and Divestitures for more information. The unrealized gains (losses) on commodity derivatives associated with the Haynesville Divestiture are offset by an equal amount recorded within "Net gain (loss) from asset sales, inclusive of restructuring costs" on the Condensed Consolidated Statements of Operations.

Leases (Notes)

Leases (Notes)	6 Months Ended
	Jun. 30, 2019
Operating Leased Assets [Line Items]
Leases of Lessee Disclosure [Text Block]	Adoption of ASC Topic 842, Leases On January 1, 2019, QEP adopted ASC Topic 842, Leases , using the modified retrospective approach, which was applied to historical leases that were still effective as of January 1, 2019. Results for reporting periods beginning January 1, 2019, are presented in accordance with ASC Topic 842, while prior period amounts are reported in accordance with historical accounting treatment under ASC Topic 840, Leases . In accordance with the adoption of ASC Topic 842, QEP now records a net operating lease right-of-use (ROU) asset and operating lease liability on the Condensed Consolidated Balance Sheets for all operating leases with a contract term in excess of 12 months. Prior to the adoption of ASC Topic 842, these same leases were treated as operating leases under ASC Topic 840 and therefore were not recorded on the December 31, 2018 Consolidated Balance Sheets. There was no impact to retained earnings and no significant impact on the Condensed Consolidated Statement of Operations or the Condensed Consolidated Statement of Cash Flows as a result of adopting ASC Topic 842. Lease Recognition QEP enters into contractual lease arrangements to rent office space, compressors, generators, drilling rigs and other equipment from third-party lessors. ROU assets represent QEP’s right to use an underlying asset for the lease term and lease liabilities represent QEP’s obligation to make future lease payments arising from the lease. Operating lease ROU assets and liabilities are recorded at commencement date based on the present value of lease payments over the lease term. Leases with an initial term of 12 months or less are not recorded on the Condensed Consolidated Balance Sheets. The Company recognizes lease expense for these short-term leases on a straight-line basis over the lease term. With the exception of generators, QEP does not account for lease components separately from the non-lease components. The contractual consideration provided under QEP's leased generators is allocated between lease components, such as equipment, and non-lease components, such as maintenance service fees, based on estimated costs from the vendor. QEP uses the implicit interest rate when readily determinable. However, most of QEP's lease agreements do not provide an implicit interest rate. As such, QEP uses its incremental borrowing rate based on the information available at commencement date of the contract in determining the present value of future lease payments. The incremental borrowing rate is calculated using a risk-free interest rate adjusted for QEP's risk. The operating lease ROU asset also includes any lease incentives received in the recognition of the present value of future lease payments. Certain of QEP's leases may also include escalation clauses or options to extend or terminate the lease. These options are included in the present value recorded for the leases when it is reasonably certain that QEP will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. QEP determines if an arrangement is a lease at inception of the contract and records the resulting operating lease asset on the Condensed Consolidated Balance Sheets as “Operating lease right-of-use assets, net” with offsetting liabilities recorded as “Current operating lease liabilities” and “Operating lease liabilities.” QEP recognizes a lease in the financial statements when the arrangement either explicitly or implicitly involves property, plant, or equipment (PP&E), the contract terms are dependent on the use of the PP&E, and QEP has the ability or right to operate the PP&E or to direct others to operate the PP&E and receive the majority of the economic benefits of the assets. As of June 30, 2019 , QEP does not have any financing leases. Lease costs represent the straight-line lease expense of ROU assets and short-term leases. The components of lease cost are classified as follows: Three Months Ended Six Months Ended June 30, 2019 (1) June 30, 2019 (1) Lease Cost included in the Condensed Consolidated Balance Sheets (in millions) Property, Plant and Equipment acquisitions (2) $ 4.1 $ 8.8 Three Months Ended Six Months Ended June 30, 2019 (1) June 30, 2019 (1) Lease Cost included in the Condensed Consolidated Statement of Operations (in millions) Lease operating expense $ 3.0 $ 6.1 Gathering and other expense 2.3 3.8 General and administrative 1.6 3.2 Total lease cost $ 11.0 $ 21.9 ____________________________ (1) Prior periods are not presented as prior period amounts have not been adjusted under the modified retrospective method for the new lease recognition rule. Refer to Note 1 – Basis of Presentation for additional information. (2) Represents short-term lease capital expenditures related to drilling rigs for the three and six months ended June 30, 2019 . These costs are capitalized as a part of "Proved properties" on the Condensed Consolidated Balance Sheets. Lease term and discount rate related to the Company's leases are as follows: Three Months Ended Six Months Ended June 30, 2019 (1) June 30, 2019 (1) Weighted-average remaining lease term (years) 3.6 3.6 Weighted-average discount rate 7.7 % 7.7 % ____________________________ (1) Prior periods are not presented as prior period amounts have not been adjusted under the modified retrospective method for the new lease recognition rule. Refer to Note 1 – Basis of Presentation for additional information. Refer to Note 11 – Commitments and Contingencies

Restructuring Costs

Restructuring Costs	6 Months Ended
	Jun. 30, 2019
Restructuring [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	QEP has incurred or expects to incur various restructuring costs associated with contractual termination benefits including severance, accelerated vesting of share-based compensation and other expenses. The termination benefits will be accounted for under ASC 712, Compensation – Nonretirement Postemployment Benefits and ASC 718, Compensation – Stock Compensation . Restructuring costs recognized are summarized below: Total recognized Recognized in "General and administrative" Recognized in "Net gain (loss) from asset sales, inclusive of restructuring costs" Recognized in "Interest and other income (expense)" Three Months Ended June 30, 2019 (in millions) Termination benefits $ (0.1 ) $ (0.1 ) $ — $ — Office lease termination costs — — — — Accelerated share-based compensation (1) 1.3 1.3 — — Retention expense (including share-based compensation) 4.8 4.8 — — Pension and Medical Plan curtailment 0.1 — — 0.1 Total restructuring costs $ 6.1 $ 6.0 $ — $ 0.1 Six Months Ended June 30, 2019 Termination benefits $ 6.7 $ 6.6 $ 0.1 $ — Office lease termination costs 0.6 0.6 — — Accelerated share-based compensation (1) 9.7 8.2 1.5 — Retention expense (including share-based compensation) 10.9 10.9 — — Pension and Medical Plan curtailment (0.4 ) — (0.2 ) (0.2 ) Total restructuring costs $ 27.5 $ 26.3 $ 1.4 $ (0.2 ) Three Months Ended June 30, 2018 Termination benefits $ 3.6 $ 1.7 $ 1.9 — Office lease termination costs 0.3 0.3 — — Accelerated share-based compensation 1.2 1.2 — — Retention expense (including share-based compensation) 6.3 6.3 — — Total restructuring costs $ 11.4 $ 9.5 $ 1.9 $ — Six Months Ended June 30, 2018 Termination benefits $ 7.0 $ 5.1 $ 1.9 — Office lease termination costs 0.3 0.3 — — Accelerated share-based compensation 4.0 4.0 — — Retention expense (including share-based compensation) 8.0 8.0 — — Total restructuring costs $ 19.3 $ 17.4 $ 1.9 $ — ____________________________ (1) Accelerated share-based compensation represents the additional expense or loss recognized in the Condensed Consolidated Statement of Operations for the three and six months ended June 30, 2019 . Total accelerated share based compensation was $2.8 million and $21.7 million for the three and six months ended June 30, 2019 , respectively, and was determined based on the contractual vesting date, with $1.3 million and $9.7 million recognized during the three and six months ended June 30, 2019 , respectively, as shown above, and the remaining amount recognized in prior periods. Costs recognized from inception to June 30, 2019 (1) Total remaining costs expected to be incurred (in millions) Termination benefits $ 38.9 $ — (2) Office lease termination costs 1.6 — (2) Accelerated share-based compensation 21.0 — (2) Retention expense (including share-based compensation) 29.7 10.1 Pension and Medical Plan curtailment (0.2 ) — (2) Total restructuring costs $ 91.0 $ 10.1 ____________________________ (1) Represents costs incurred since February 2018 when QEP's Board of Directors approved certain strategic and financial initiatives. (2) Due to the nature of the strategic initiatives, as of June 30, 2019 , the Company is not able to reasonably estimate the total cost to be incurred in connection with these restructurings. The following table is a reconciliation of QEP's restructuring liability, which is included within "Accounts payable and accrued expenses" on the Condensed Consolidated Balance Sheets. Restructuring liability Termination benefits Office lease termination costs Accelerated share-based compensation Retention expense Pension curtailment Total (in millions) Balance at December 31, 2018 $ 19.5 $ — $ — $ 10.8 $ — $ 30.3 Costs incurred and charged to expense 6.7 0.6 9.7 10.9 (0.4 ) 27.5 Costs paid or otherwise settled (23.9 ) (0.6 ) (9.7 ) (15.9 ) 0.4 (49.7 ) Balance at June 30, 2019 $ 2.3 $ — $ — $ 5.8 $ — $ 8.1

Debt

Debt	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt [Text Block]	As of the indicated dates, the principal amount of QEP's debt consisted of the following: June 30, December 31, (in millions) Revolving Credit Facility due 2022 $ — $ 430.0 6.80% Senior Notes due 2020 51.7 51.7 6.875% Senior Notes due 2021 397.6 397.6 5.375% Senior Notes due 2022 500.0 500.0 5.25% Senior Notes due 2023 650.0 650.0 5.625% Senior Notes due 2026 500.0 500.0 Less: unamortized discount and unamortized debt issuance costs (19.5 ) (22.2 ) Total principal amount of debt (including current portion) 2,079.8 2,507.1 Less: current portion of long-term debt (51.7 ) — Total long-term debt outstanding $ 2,028.1 $ 2,507.1 Of the total debt outstanding on June 30, 2019 , the 6.80% Senior Notes due March 1, 2020 , the 6.875% Senior Notes due March 1, 2021 , the 5.375% Senior Notes due October 1, 2022 and the 5.25% Senior Notes due May 1, 2023 , will mature within the next five years . In addition, the revolving credit facility matures on September 1, 2022 . Credit Facility QEP's revolving credit facility, which matures, subject to satisfaction of certain conditions, in September 2022, provides for loan commitments of $1.25 billion . The credit facility provides for borrowings at short-term interest rates and contains customary covenants and restrictions. The credit agreement governing QEP's revolving credit facility contains financial covenants (that are defined in the credit agreement) that limit the amount of debt the Company can incur and may limit the amount available to be drawn under the credit facility including: (i) a net funded debt to capitalization ratio that may not exceed 60%, (ii) a leverage ratio under which net funded debt may not exceed 3.75 times consolidated EBITDA (as defined in the credit agreement) and (iii) a present value coverage ratio under which the present value of the Company's proved reserves must exceed net funded debt by 1.40 times through December 31, 2019, and must exceed net funded debt by 1.50 times at any time on or after January 1, 2020. At June 30, 2019 and December 31, 2018 , QEP was in compliance with the covenants under the credit agreement. During the six months ended June 30, 2019 , QEP's weighted-average interest rate on borrowings from its credit facility was 4.73% . As of June 30, 2019 , QEP had no borrowings outstanding and $2.9 million in letters of credit outstanding under the credit facility. As of December 31, 2018 , QEP had $430.0 million of borrowings outstanding and $0.3 million in letters of credit outstanding under the credit facility. Senior Notes At June 30, 2019 , the Company had $2,099.3 million in principal amount of senior notes outstanding with maturities ranging from March 1, 2020 to March 1, 2026 and coupons ranging from 5.25% to 6.875% . The senior notes pay interest semi-annually, are unsecured senior obligations and rank equally with all of QEP's other existing and future unsecured and senior obligations. QEP may redeem some or all of its senior notes at any time before their maturity at a redemption price based on a make-whole amount plus accrued and unpaid interest to the date of redemption. The indentures governing QEP's senior notes contain customary events of default and covenants that may limit QEP's ability to, among other things, place liens on its property or assets.

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingencies [Text Block]	The Company is involved in various commercial and regulatory claims, litigation and other legal proceedings that arise in the ordinary course of its business. In each reporting period, the Company assesses these claims in an effort to determine the degree of probability and range of possible loss for potential accrual in its Condensed Consolidated Financial Statements. In accordance with ASC 450, Contingencies , an accrual is recorded for a material loss contingency when its occurrence is probable and damages are reasonably estimable based on the anticipated most likely outcome or the minimum amount within a range of possible outcomes. Legal proceedings are inherently unpredictable and unfavorable resolutions can occur. Assessing contingencies is highly subjective and requires judgment about uncertain future events. When evaluating contingencies related to legal proceedings, the Company may be unable to estimate losses due to a number of factors, including potential defenses, the procedural status of the matter in question, the presence of complex legal and/or factual issues and the ongoing discovery and/or development of information important to the matter. Landowner Litigation – In October 2017, the owners of certain surface and mineral interests in Martin and Andrews County, Texas, filed suit against QEP, alleging QEP improperly used the surface of the properties and failed to correctly pay royalties, and seeking money damages and a declaratory judgment that portions of the oil and gas leases covering the properties are no longer in effect. Mandan, Hidatsa and Arikara Nation ("MHA Nation") Title Dispute – In June 2018, the MHA Nation notified QEP of its position that QEP has no valid lease covering certain minerals underlying the Missouri and Little Missouri Riverbeds on the Fort Berthold Reservation in North Dakota. The MHA Nation also passed a resolution purporting to rescind those portions of QEP's IMDA lease covering the disputed minerals underlying the Missouri River. The Company is unable to make an estimate of the range of reasonably possible loss related to its contingencies. Commitments QEP has entered into contractual lease arrangements to rent office space, compressors, generators, drilling rigs and other equipment from third-party lessors. On January 1, 2019, QEP adopted ASC Topic 842, Leases , using the modified retrospective approach. Refer to Note 8 – Leases for additional information. As of June 30, 2019 , minimum future payments, including imputed interest, for long-term operating leases under the scope of ASC 842 are as follows: Year Amount (in millions) 2019 $ 12.4 2020 $ 21.1 2021 $ 19.4 2022 $ 14.9 2023 $ 9.4 After 2023 $ 0.5 Less: Interest (1) $ (11.0 ) Present value of lease liabilities (2) $ 66.7 ____________________________ (1) Calculated using the estimated or stated interest rate for each lease. (2) Of the total present value of lease liabilities, $18.8 million was recorded in "Current operating lease liabilities" and $47.9 million was recorded in "Operating lease liabilities" on the Condensed Consolidated Balance Sheets. As of December 31, 2018 , minimum future contractual payments for long-term operating leases under the scope of ASC 840 are as follows: Year Amount (in millions) 2019 $ 17.4 2020 $ 13.8 2021 $ 9.1 2022 $ 7.4 2023 $ 4.5 After 2023 $ —

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation [Text Block]	In 2018, QEP's Board of Directors and QEP's shareholders approved the QEP Resources, Inc. 2018 Long-Term Incentive Plan (LTIP), which replaces the 2010 Long-Term Stock Incentive Plan (LTSIP) and provides for the issuance of up to 10.0 million shares such that the Board of Directors may grant long-term incentive compensation. QEP has issued stock options, restricted share awards, and restricted share units under its LTSIP or LTIP and awards performance share units under its Cash Incentive Plan (CIP) to certain officers, employees and non-employee directors. Grants issued prior to May 15, 2018 were under the LTSIP and grants issued on or after May 15, 2018 are under the LTIP. QEP recognizes the expense over the vesting periods for the stock options, restricted share awards, restricted share units and performance share units. There were 8.3 million shares available for future grants under the LTIP at June 30, 2019 . Share-based compensation expense is generally recognized within "General and administrative" expense on the Condensed Consolidated Statements of Operations and is summarized in the table below. During the three and six months ended June 30, 2019 , the Company recorded an additional $1.3 million and $9.7 million , respectively, of share-based compensation expense related to the acceleration of vesting that occurred as part of the restructuring program, of which $1.5 million was recorded in "Net gain (loss) from asset sales, inclusive of restructuring costs" on the Condensed Consolidated Statement of Operations during the six months ended June 30, 2019 and the remaining $1.3 million and $8.2 million , respectively, is included in the table below. During the three and six months ended June 30, 2018 , the Company recorded an additional $1.2 million and $4.0 million , respectively of share-based compensation expense, related to the acceleration of vesting that occurred as part of the restructuring program, all of which is included in the table below. Refer to Note 9 – Restructuring for additional information. Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 (in millions) Stock options $ — $ 0.2 $ 0.3 $ 0.7 Restricted share awards 4.8 6.8 10.9 15.6 Performance share units 0.3 5.1 5.5 7.0 Restricted share units 0.1 0.1 0.2 0.1 Total share-based compensation expense $ 5.2 $ 12.2 $ 16.9 $ 23.4 Stock Options QEP uses the Black-Scholes-Merton mathematical model to estimate the fair value of stock option awards at the date of grant. Fair value calculations rely upon subjective assumptions used in the mathematical model and may not be representative of future results. The Black-Scholes-Merton model is intended for calculating the value of stock options not traded on an exchange. The Company utilizes the "simplified" method to estimate the expected term of the stock options granted as there is limited historical exercise data available in estimating the expected term of the stock options. QEP uses a historical volatility method to estimate the fair value of stock option awards and the risk-free interest rate is based on the yield on U.S. Treasury strips with maturities similar to those of the expected term of the stock options. The stock options typically vest in equal installments over three years from the grant date and are exercisable immediately upon vesting through the seventh anniversary of the grant date. To fulfill options exercised, QEP either reissues treasury stock or issues new shares. The Company recognizes forfeitures of stock options as they occur. During the six months ended June 30, 2019 , QEP did not issue stock options. Stock option transactions under the terms of the LTSIP are summarized below: Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (per share) (in years) (in millions) Outstanding at December 31, 2018 2,098,933 $ 22.27 Cancelled (283,029 ) 30.90 Outstanding at June 30, 2019 1,815,904 $ 20.93 2.80 $ — Options Exercisable at June 30, 2019 1,761,139 $ 21.08 2.74 $ — Unvested Options at June 30, 2019 54,765 $ 15.92 4.69 $ — During the six months ended June 30, 2019 there were no exercises of stock options. As of June 30, 2019 , $0.1 million of unrecognized compensation expense related to stock options granted under the LTSIP is expected to be recognized over a weighted-average vesting period of 0.78 years. The weighted-average vesting period may be reduced due to accelerated vestings under the restructuring program. Refer to Note 9 – Restructuring for additional information. Restricted Share Awards Restricted share award grants typically vest in equal installments over three years from the grant date. The grant date fair value is determined based on the closing bid price of the Company's common stock on the grant date. The Company recognizes restricted share forfeitures as they occur. The total fair value of restricted share awards that vested during the six months ended June 30, 2019 and 2018 was $25.0 million and $24.6 million , respectively. The weighted-average grant date fair value of restricted share awards was $7.98 per share and $9.55 per share for the six months ended June 30, 2019 and 2018 , respectively. As of June 30, 2019 , $18.8 million of unrecognized compensation expense related to restricted share awards granted under the LTSIP and LTIP is expected to be recognized over a weighted-average vesting period of 2.31 years. The weighted-average vesting period may be reduced due to accelerated vestings under the restructuring program. Refer to Note 9 – Restructuring for additional information. Transactions involving restricted share awards under the terms of the LTSIP and LTIP are summarized below: Restricted Share Awards Outstanding Weighted-Average Grant Date Fair Value (per share) Unvested balance at December 31, 2018 3,822,133 $ 10.76 Granted 2,217,794 7.98 Vested (2,261,323 ) 11.05 Forfeited (178,985 ) 9.23 Unvested balance at June 30, 2019 3,599,619 $ 8.94 Performance Share Units The payouts for performance share units are dependent upon the Company's total shareholder return compared to a group of its peers over three years . The awards are denominated in share units and have historically been paid in cash. The Company has the option to settle earned awards in cash or shares of common stock under the Company's LTIP; however, as of June 30, 2019 , the Company expects to settle all awards in cash under the CIP. These awards are classified as liabilities and are included within "Other long-term liabilities" on the Condensed Consolidated Balance Sheets. As these awards are dependent upon the Company's total shareholder return and stock price, they are remeasured at fair value at the end of each reporting period. The Company paid $11.4 million and $2.0 million for vested performance share units during the six months ended June 30, 2019 and 2018 , respectively. The weighted-average grant date fair value of the performance share units granted during the six months ended June 30, 2019 and 2018 was $7.93 and $9.55 per share, respectively. As of June 30, 2019 , $7.2 million of unrecognized compensation cost, which represents the unvested portion of the fair market value of performance shares granted, is expected to be recognized over a weighted-average vesting period of 2.33 years. The weighted-average vesting period may be reduced due to accelerated vestings under the restructuring program. Refer to Note 9 – Restructuring for additional information. Transactions involving performance share units under the terms of the CIP are summarized below: Performance Share Units Outstanding Weighted-Average Grant Date Fair Value (per share) Unvested balance at December 31, 2018 1,559,312 $ 11.47 Granted 589,412 7.93 Vested and paid (1,117,848 ) 10.73 Unvested balance at June 30, 2019 1,030,876 $ 9.63 Restricted Share Units Employees may elect to defer their grants of restricted share awards and these deferred awards are designated as restricted share units. Restricted share units vest over three years and are deferred into the Company's nonqualified, unfunded deferred compensation plan at the time of vesting. These awards are ultimately paid in cash. They are classified as liabilities in "Other long-term liabilities" on the Condensed Consolidated Balance Sheets and are measured at fair value at the end of each reporting period. The weighted-average grant date fair value of the restricted share units was $7.93 and $9.55 per share for the six months ended June 30, 2019 and 2018 , respectively. As of June 30, 2019 , $0.2 million of unrecognized compensation cost, which represents the unvested portion of the fair market value of restricted share units granted, is expected to be recognized over a weighted-average vesting period of 1.64 years. The weighted-average vesting period may be reduced due to accelerated vestings under the restructuring program. Refer to Note 9 – Restructuring for additional information. Transactions involving restricted share units under the terms of the LTSIP and LTIP are summarized below: Restricted Share Units Outstanding Weighted-Average Grant Date Fair Value (per share) Unvested balance at December 31, 2018 42,675 $ 10.47 Granted 37,224 7.93 Vested and paid (36,392 ) 10.67 Unvested balance at June 30, 2019 43,507 $ 8.16

Employee Benefits

Employee Benefits	6 Months Ended
	Jun. 30, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee Benefits [Text Block]	Pension and Other Postretirement Benefits The Company provides pension and other postretirement benefits to certain employees through three retiree benefit plans: the QEP Resources, Inc. Retirement Plan (the Pension Plan), the Supplemental Executive Retirement Plan (the SERP), and a postretirement medical plan (the Medical Plan). The Pension Plan is a closed, qualified, defined-benefit pension plan that is funded and provides pension benefits to certain QEP employees. During the six months ended June 30, 2019 , the Company made contributions of $5.0 million to the Pension Plan and does not expect to make any additional contributions during the remainder of 2019 . Contributions to the Pension Plan increase plan assets. The Pension Plan was amended in June 2015 and was frozen effective January 1, 2016, such that employees do not earn additional defined benefits for future services. The SERP is a nonqualified retirement plan that is unfunded and provides pension benefits to certain QEP employees. During the six months ended June 30, 2019 , the Company made contributions of $0.2 million to the SERP and expects to contribute an additional $0.3 million to the SERP during the remainder of 2019 . Contributions to the SERP are used to fund current benefit payments. The SERP was amended and restated in June 2015 and was closed to new participants effective January 1, 2016. The Medical Plan is a self-insured plan. It is unfunded and provides other postretirement benefits including certain health care and life insurance benefits for certain retired QEP employees. During the six months ended June 30, 2019 , the Company made contributions of $0.1 million to the Medical Plan and expects to contribute $0.2 million to the Medical Plan during the remainder of 2019 . Contributions to the Medical Plan are used to fund current benefit payments. In February 2017, the Company changed the eligibility requirements for active employees eligible for the Medical Plan, as well as retirees currently enrolled. Effective July 1, 2017, the Company no longer offers the Medical Plan to retirees and spouses that are both Medicare eligible. In addition, the Company no longer offers life insurance to individuals retiring on or after July 1, 2017. The Company's implementation of its strategic initiatives may trigger curtailments related to the Pension Plan, SERP and/or Medical Plan upon the closing of any transaction. Refer to Note 9 – Restructuring for more information. During the six months ended June 30, 2019 , the Company recognized a $0.4 million pension curtailment gain related to strategic initiatives, of which $0.5 million of curtailment gain was related to the Haynesville Divestiture and included in "Interest and other income (expense)" and "Net gain (loss) from asset sales, inclusive of restructuring costs" on the Condensed Consolidated Statements of Operations, and $0.1 million of curtailment loss was related to corporate restructuring activities and included as "Interest and other income (expense)" on the Condensed Consolidated Statements of Operations. The Company recognizes service costs related to SERP and Medical Plan benefits on the Condensed Consolidated Statements of Operations within "General and administrative" expense. All other expenses related to the Pension Plan, SERP and Medical Plan are recognized on the Condensed Consolidated Statements of Operations within "Interest and other income (expense)". The following table sets forth the Company's net periodic benefit costs related to its Pension Plan, SERP and Medical Plan: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Pension Plan and SERP benefits (in millions) Service cost $ — $ 0.2 $ 0.1 $ 0.4 Interest cost 1.2 1.1 2.4 2.2 Expected return on plan assets (1.4 ) (1.5 ) (2.9 ) (2.9 ) Amortization of prior service costs (1) 0.1 0.2 0.2 0.4 Amortization of actuarial losses (1) — 0.3 0.1 0.6 Curtailment (gain) loss (2) 0.1 — 0.4 — Periodic expense $ — $ 0.3 $ 0.3 $ 0.7 Medical Plan benefits Interest cost $ 0.1 $ 0.1 $ 0.1 $ 0.1 Amortization of prior service costs (1) — — — (0.1 ) Curtailment (gain) loss (2) — — (0.8 ) — Periodic expense $ 0.1 $ 0.1 $ (0.7 ) $ — ____________________________ (1) Amortization of prior service costs and actuarial losses out of accumulated other comprehensive income (loss) are recognized on the Condensed Consolidated Statements of Operations within "Interest and other income (expense)". (2) A curtailment is recognized when there is a significant reduction in, or an elimination of, defined benefit accruals for current employees' future services. The net curtailment gain between the SERP and Medical Plan of $0.4 million is related to the Haynesville Divestiture and corporate restructuring activities. Of the $0.4 million curtailment gain recognized, $0.2 million was recognized on the Condensed Consolidated Statements of Operations within "Interest and other income (expense)" and $0.2 million was recognized on the Condensed Consolidated Statements of Operations within "Net gain (loss) from asset sales, inclusive of restructuring costs" for the six months ended June 30, 2019 . Employee Investment Plan QEP employees may participate in the QEP Employee Investment Plan, a defined-contribution plan (the 401(k) Plan). The 401(k) Plan allows eligible employees to make investments, including purchasing shares of QEP common stock, through payroll deduction at the current fair market value on the transaction date. Both employees and QEP make contributions to the 401(k) Plan. The Company may contribute a discretionary portion beyond the Company's matching contribution to employees not in the Pension Plan or SERP. During the six months ended June 30, 2019 , the Company made contributions of $2.6 million to the 401(k) Plan and expects to contribute an additional $1.8 million to the 401(k) Plan during the remainder of 2019 . The Company recognizes expense equal to its yearly contributions. Due to the Company's strategic initiatives, the amount to be contributed to the 401(k) Plan may change. Refer to Note 9 – Restructuring for more information. As a result of freezing benefits under the Pension Plan, the 401(k) Plan and a nonqualified, unfunded deferred compensation plan (the Wrap Plan) were amended to allow the Company to make discretionary contributions (Company Transition Credits) to eligible participants. Eligible participants are certain employees who were active participants in the Pension Plan on December 31, 2015. During the six months ended June 30, 2019 , the Company did not make a discretionary contribution to active participants of the Pension Plan but expects to contribute $0.1 million to eligible participants during the fourth quarter of 2019 .

Subsequent Event (Notes)

Subsequent Event (Notes)	6 Months Ended
	Jun. 30, 2019
Subsequent Event [Line Items]
Subsequent Events [Text Block]	Subsequent to June 30, 2019 , QEP's Board of Directors completed its comprehensive review of strategic alternatives and determined that the best alternative for QEP's shareholders is to move forward as an independent company. The Company is not able to reasonably estimate the future costs to be incurred in connection with the review of strategic alternatives. On August 6, 2019 , QEP's Board of Directors approved the reinstatement of a quarterly cash dividend of $0.02 per share of common stock, payable on September 10, 2019 to shareholders of record on August 20, 2019 .

Basis of Presentation Restricte

Basis of Presentation Restricted Cash (Tables)	6 Months Ended
	Jun. 30, 2019
Restricted Cash [Abstract]
Restrictions on Cash and Cash Equivalents [Table Text Block]	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Condensed Consolidated Balance Sheets to the amounts shown in the Condensed Consolidated Statements of Cash Flows: June 30, 2019 2018 (in millions) Cash and cash equivalents $ 97.1 $ — Restricted cash (1) 29.2 26.1 Total cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 126.3 $ 26.1 _______________________ (1) As of June 30, 2019 and 2018

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue Recognition [Abstract]
Revenue Recognition [Table Text Block]	The following tables present QEP's revenues that are disaggregated by revenue source and by geographic area. Transportation and processing costs in the following table are not all of the transportation and processing costs that QEP incurs, only the expenses that are netted against revenues pursuant to ASC Topic 606. Oil and condensate sales Gas sales NGL sales Transportation and processing costs included in revenue Oil and condensate, gas and NGL sales, as reported (in millions) Three Months Ended June 30, 2019 Northern Region Williston Basin $ 107.5 $ 7.5 $ 5.8 $ (8.9 ) $ 111.9 Other Northern 0.5 0.1 — — 0.6 Southern Region Permian Basin 177.6 (0.6 ) 8.5 (3.8 ) 181.7 Other Southern 0.1 0.3 — — 0.4 Total oil and condensate, gas and NGL sales $ 285.7 $ 7.3 $ 14.3 $ (12.7 ) $ 294.6 Three Months Ended June 30, 2018 Northern Region Williston Basin $ 207.6 $ 8.4 $ 14.7 $ (10.7 ) $ 220.0 Uinta Basin 9.5 7.9 1.7 — 19.1 Other Northern 0.9 0.2 0.1 — 1.2 Southern Region Permian Basin 190.3 3.2 9.9 (1.7 ) 201.7 Haynesville/Cotton Valley 0.2 77.9 — — 78.1 Other Southern — 0.2 — — 0.2 Total oil and condensate, gas and NGL sales $ 408.5 $ 97.8 $ 26.4 $ (12.4 ) $ 520.3 Oil and condensate sales Gas sales NGL sales Transportation and processing costs included in revenue Oil and condensate, gas and NGL sales, as reported (in millions) Six Months Ended June 30, 2019 Northern Region Williston Basin $ 217.4 $ 20.0 $ 13.2 $ (19.0 ) $ 231.6 Other Northern 0.9 0.3 — — 1.2 Southern Region Permian Basin 316.8 4.0 18.0 (7.5 ) 331.3 Other Southern 0.1 6.0 — — 6.1 Total oil and condensate, gas and NGL sales $ 535.2 $ 30.3 $ 31.2 $ (26.5 ) $ 570.2 Six Months Ended June 30, 2018 Northern Region Williston Basin $ 368.1 $ 18.2 $ 26.5 $ (20.6 ) $ 392.2 Uinta Basin 17.9 18.0 3.4 — 39.3 Other Northern 2.8 1.2 (0.1 ) — 3.9 Southern Region Permian Basin 320.1 7.8 16.4 (4.5 ) 339.8 Haynesville/Cotton Valley 0.6 154.3 — — 154.9 Other Southern (0.3 ) 0.3 — — — Total oil and condensate, gas and NGL sales $ 709.2 $ 199.8 $ 46.2 $ (25.1 ) $ 930.1

Acquisitions & Divestitures Sch

Acquisitions & Divestitures Schedule of Assets and Liabilities Held for Sale (Tables)	12 Months Ended
	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncurrent Assets and Liabilities Held for Sale [Table Text Block]	The following table presents the carrying amounts of the major classes of assets and liabilities related to the Haynesville Divestiture classified as noncurrent assets and liabilities held for sale on the Condensed Consolidated Balance Sheets: December 31, 2018 (1) (in millions) Assets Current assets, total $ 1.2 Net Property, Plant and Equipment 683.7 Other noncurrent assets 7.8 Noncurrent assets held for sale $ 692.7 Liabilities Current liabilities, total $ 3.4 Asset retirement obligations, current 0.7 Asset retirement obligations, long-term 56.9 Other long-term liabilities 0.3 Other long-term liabilities held for sale $ 61.3

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Components of basic and diluted shares used in EPS [Table Text Block]	The following is a reconciliation of the components of basic and diluted shares used in the EPS calculation: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 (in millions) Weighted-average basic common shares outstanding 238.0 237.0 237.5 238.9 Potential number of shares issuable upon exercise of in-the-money stock options under the Long-Term Stock Incentive Plan — — — — Average diluted common shares outstanding 238.0 237.0 237.5 238.9

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2019
Asset Retirement Obligation [Abstract]
Asset Retirement Obligation Disclosure [Text Block]	Asset Retirement Obligations June 30, December 31, 2019 2018 Balance Sheet line item (in millions) Current: Asset retirement obligations, current liability $ 6.8 $ 5.1 Long-term: Asset retirement obligations 94.6 96.9 Other long-term liabilities held for sale — 57.6 Total ARO Liability $ 101.4 $ 159.6
Schedule of Change in Asset Retirement Obligation [Table Text Block]	The following is a reconciliation of the changes in the Company's ARO for the period specified below: Asset Retirement Obligations (in millions) ARO liability at January 1, 2019 $ 159.6 Accretion 3.1 Additions 0.4 Revisions (0.3 ) Liabilities related to assets sold (1) (60.7 ) Liabilities settled (0.7 ) ARO liability at June 30, 2019 $ 101.4 _______________________ (1) Liabilities related to assets sold during the six months ended June 30, 2019 , includes $57.6 million related to the Haynesville Divestiture (refer to Note 3 – Acquisitions and Divestitures for more information).	[1]
[1]	(1) Liabilities related to assets sold during the six months ended June 30, 2019 , includes $57.6 million related to the Haynesville Divestiture (refer to Note 3 – Acquisitions and Divestitures for more information).

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets and liabilities [Table Text Block]	The fair value of financial assets and liabilities at June 30, 2019 and December 31, 2018 , is shown in the table below: Fair Value Measurements Gross Amounts of Assets and Liabilities Netting Adjustments (1) Net Amounts Presented on the Condensed Consolidated Balance Sheets Level 1 Level 2 Level 3 (in millions) Financial Assets June 30, 2019 Fair value of derivative contracts – short-term $ — $ 2.7 $ — $ — $ 2.7 Fair value of derivative contracts – long-term — 15.2 — — 15.2 Total financial assets $ — $ 17.9 $ — $ — $ 17.9 Financial Liabilities Fair value of derivative contracts – short-term $ — $ 17.6 $ — $ — $ 17.6 Fair value of derivative contracts – long-term — 0.9 — — 0.9 Total financial liabilities $ — $ 18.5 $ — $ — $ 18.5 December 31, 2018 Financial Assets Fair value of derivative contracts – short-term (2) $ — $ 88.2 $ — $ (0.4 ) $ 87.8 Fair value of derivative contracts – long-term — 35.4 — — 35.4 Total financial assets $ — $ 123.6 $ — $ (0.4 ) $ 123.2 Financial Liabilities Fair value of derivative contracts – short-term $ — $ 0.4 $ — $ (0.4 ) $ — Fair value of derivative contracts – long-term — 0.7 — — 0.7 Total financial liabilities $ — $ 1.1 $ — $ (0.4 ) $ 0.7 _______________________ (1) The Company nets its derivative contract assets and liabilities outstanding with the same counterparty on the Condensed Consolidated Balance Sheets for the contracts that contain netting provisions. Refer to Note 7 – Derivative Contracts for additional information regarding the Company's derivative contracts.
Fair value and related carrying amount of certain financial instruments [Table Text Block]	The following table discloses the fair value and related carrying amount of certain financial instruments not disclosed in other Notes to the Condensed Consolidated Financial Statements in this Quarterly Report on Form 10-Q: Carrying Amount Level 1 Fair Value Carrying Amount Level 1 Fair Value June 30, 2019 December 31, 2018 Financial Assets (in millions) Cash and cash equivalents $ 97.1 $ 97.1 $ — $ — Financial Liabilities Checks outstanding in excess of cash balances $ 5.3 $ 5.3 $ 14.6 $ 14.6 Total debt outstanding $ 2,079.8 $ 2,042.5 $ 2,507.1 $ 2,350.5

Derivative Contracts (Tables)

Derivative Contracts (Tables)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	Derivative Contracts – Production The following table presents QEP's volumes and average prices for its commodity derivative swap contracts as of June 30, 2019 : Year Index Total Volumes Average Swap Price per Unit (in millions) Oil sales (bbls) ($/bbl) 2019 NYMEX WTI 6.6 $ 55.24 2019 ICE Brent 0.9 $ 66.73 2019 Argus WTI Houston 0.2 $ 65.70 2020 NYMEX WTI 6.2 $ 60.07 2020 Argus WTI Midland 0.7 $ 60.00 QEP uses oil basis swaps, combined with NYMEX WTI fixed-price swaps, to achieve fixed price swaps for the location at which it sells its physical production. The following table presents details of QEP's oil basis swaps as of June 30, 2019 : Year Index Basis Total Volumes Weighted-Average Differential (in millions) Oil sales (bbls) ($/bbl) 2019 NYMEX WTI Argus WTI Midland 3.3 $ (2.22 ) 2019 NYMEX WTI Argus WTI Houston 0.9 $ 3.69 2020 NYMEX WTI Argus WTI Midland 4.4 $ (0.02 ) 2020 (January - June) NYMEX WTI Argus WTI Houston 0.4 $ 3.75
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table identifies the Condensed Consolidated Balance Sheet location of QEP's outstanding derivative contracts on a gross contract basis as opposed to the net contract basis presentation on the Condensed Consolidated Balance Sheets and the related fair values at the balance sheet dates: Gross asset derivative Gross liability derivative Balance Sheet line item June 30, December 31, June 30, December 31, Current: (in millions) Commodity (1) Fair value of derivative contracts $ 2.7 $ 88.2 $ 17.6 $ 0.4 Long-term: Commodity Fair value of derivative contracts 15.2 35.4 0.9 0.7 Total derivative instruments $ 17.9 $ 123.6 $ 18.5 $ 1.1
Derivative Instruments, Gain (Loss) [Table Text Block]	The effects of the change in fair value and settlement of QEP's derivative contracts recorded in "Realized and unrealized gains (losses) on derivative contracts" on the Condensed Consolidated Statements of Operations are summarized in the following table: Three Months Ended Six Months Ended Derivative contracts June 30, June 30, 2019 2018 2019 2018 Realized gains (losses) on commodity derivative contracts (in millions) Production Oil derivative contracts $ (16.0 ) $ (52.0 ) $ (19.0 ) $ (96.3 ) Gas derivative contracts — 6.4 (2.9 ) 7.3 Gas Storage Gas derivative contracts — 0.1 — 0.3 Realized gains (losses) on commodity derivative contracts (16.0 ) (45.5 ) (21.9 ) (88.7 ) Unrealized gains (losses) on commodity derivative contracts Production Oil derivative contracts 54.5 (20.6 ) (122.8 ) (27.5 ) Gas derivative contracts — (13.0 ) (0.3 ) (15.8 ) Gas Storage Gas derivative contracts — — — (0.3 ) Unrealized gains (losses) on commodity derivative contracts 54.5 (33.6 ) (123.1 ) (43.6 ) Total realized and unrealized gains (losses) on commodity derivative contracts related to production and storage $ 38.5 $ (79.1 ) $ (145.0 ) $ (132.3 ) Derivatives associated with Haynesville Divestiture Unrealized gains (losses) on commodity derivative contracts Production Gas derivative contracts — — 1.8 — Unrealized gains (losses) on commodity derivative contracts related to divestitures (1) $ — $ — $ 1.8 $ — Total realized and unrealized gains (losses) on commodity derivative contracts $ 38.5 $ (79.1 ) $ (143.2 ) $ (132.3 ) _______________________ (1) During the three and six months ended June 30, 2019 , the unrealized gains (losses) on commodity derivative contracts related to the Haynesville Divestiture were comprised of derivatives included as part of the Haynesville/Cotton Valley purchase and sale agreement, which were subsequently novated to the buyer upon the closing of the sale in January 2019. Refer to Note 3 – Acquisitions and Divestitures for more information. The unrealized gains (losses) on commodity derivatives associated with the Haynesville Divestiture are offset by an equal amount recorded within "Net gain (loss) from asset sales, inclusive of restructuring costs" on the Condensed Consolidated Statements of Operations.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Lease, Cost [Table Text Block]	Lease costs represent the straight-line lease expense of ROU assets and short-term leases. The components of lease cost are classified as follows: Three Months Ended Six Months Ended June 30, 2019 (1) June 30, 2019 (1) Lease Cost included in the Condensed Consolidated Balance Sheets (in millions) Property, Plant and Equipment acquisitions (2) $ 4.1 $ 8.8 Three Months Ended Six Months Ended June 30, 2019 (1) June 30, 2019 (1) Lease Cost included in the Condensed Consolidated Statement of Operations (in millions) Lease operating expense $ 3.0 $ 6.1 Gathering and other expense 2.3 3.8 General and administrative 1.6 3.2 Total lease cost $ 11.0 $ 21.9 ____________________________ (1) Prior periods are not presented as prior period amounts have not been adjusted under the modified retrospective method for the new lease recognition rule. Refer to Note 1 – Basis of Presentation for additional information. (2) Represents short-term lease capital expenditures related to drilling rigs for the three and six months ended June 30, 2019 . These costs are capitalized as a part of "Proved properties" on the Condensed Consolidated Balance Sheets.
Lessee, Operating Leases [Text Block]	Lease term and discount rate related to the Company's leases are as follows: Three Months Ended Six Months Ended June 30, 2019 (1) June 30, 2019 (1) Weighted-average remaining lease term (years) 3.6 3.6 Weighted-average discount rate 7.7 % 7.7 %

Restructuring Costs Restructuri

Restructuring Costs Restructuring Costs (Tables)	6 Months Ended
	Jun. 30, 2019
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Reserve by Type of Cost [Table Text Block]	Restructuring costs recognized are summarized below: Total recognized Recognized in "General and administrative" Recognized in "Net gain (loss) from asset sales, inclusive of restructuring costs" Recognized in "Interest and other income (expense)" Three Months Ended June 30, 2019 (in millions) Termination benefits $ (0.1 ) $ (0.1 ) $ — $ — Office lease termination costs — — — — Accelerated share-based compensation (1) 1.3 1.3 — — Retention expense (including share-based compensation) 4.8 4.8 — — Pension and Medical Plan curtailment 0.1 — — 0.1 Total restructuring costs $ 6.1 $ 6.0 $ — $ 0.1 Six Months Ended June 30, 2019 Termination benefits $ 6.7 $ 6.6 $ 0.1 $ — Office lease termination costs 0.6 0.6 — — Accelerated share-based compensation (1) 9.7 8.2 1.5 — Retention expense (including share-based compensation) 10.9 10.9 — — Pension and Medical Plan curtailment (0.4 ) — (0.2 ) (0.2 ) Total restructuring costs $ 27.5 $ 26.3 $ 1.4 $ (0.2 ) Three Months Ended June 30, 2018 Termination benefits $ 3.6 $ 1.7 $ 1.9 — Office lease termination costs 0.3 0.3 — — Accelerated share-based compensation 1.2 1.2 — — Retention expense (including share-based compensation) 6.3 6.3 — — Total restructuring costs $ 11.4 $ 9.5 $ 1.9 $ — Six Months Ended June 30, 2018 Termination benefits $ 7.0 $ 5.1 $ 1.9 — Office lease termination costs 0.3 0.3 — — Accelerated share-based compensation 4.0 4.0 — — Retention expense (including share-based compensation) 8.0 8.0 — — Total restructuring costs $ 19.3 $ 17.4 $ 1.9 $ —
Restructuring Costs [Table Text Block]	Costs recognized from inception to June 30, 2019 (1) Total remaining costs expected to be incurred (in millions) Termination benefits $ 38.9 $ — (2) Office lease termination costs 1.6 — (2) Accelerated share-based compensation 21.0 — (2) Retention expense (including share-based compensation) 29.7 10.1 Pension and Medical Plan curtailment (0.2 ) — (2) Total restructuring costs $ 91.0 $ 10.1 ____________________________ (1) Represents costs incurred since February 2018 when QEP's Board of Directors approved certain strategic and financial initiatives. (2) Due to the nature of the strategic initiatives, as of June 30, 2019 , the Company is not able to reasonably estimate the total cost to be incurred in connection with these restructurings.
Restructuring Costs, Liability [Table Text Block]	The following table is a reconciliation of QEP's restructuring liability, which is included within "Accounts payable and accrued expenses" on the Condensed Consolidated Balance Sheets. Restructuring liability Termination benefits Office lease termination costs Accelerated share-based compensation Retention expense Pension curtailment Total (in millions) Balance at December 31, 2018 $ 19.5 $ — $ — $ 10.8 $ — $ 30.3 Costs incurred and charged to expense 6.7 0.6 9.7 10.9 (0.4 ) 27.5 Costs paid or otherwise settled (23.9 ) (0.6 ) (9.7 ) (15.9 ) 0.4 (49.7 ) Balance at June 30, 2019 $ 2.3 $ — $ — $ 5.8 $ — $ 8.1

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt Outstanding [Table Text Block]	As of the indicated dates, the principal amount of QEP's debt consisted of the following: June 30, December 31, (in millions) Revolving Credit Facility due 2022 $ — $ 430.0 6.80% Senior Notes due 2020 51.7 51.7 6.875% Senior Notes due 2021 397.6 397.6 5.375% Senior Notes due 2022 500.0 500.0 5.25% Senior Notes due 2023 650.0 650.0 5.625% Senior Notes due 2026 500.0 500.0 Less: unamortized discount and unamortized debt issuance costs (19.5 ) (22.2 ) Total principal amount of debt (including current portion) 2,079.8 2,507.1 Less: current portion of long-term debt (51.7 ) — Total long-term debt outstanding $ 2,028.1 $ 2,507.1

Commitments and Contingencies M

Commitments and Contingencies Minimum Lease Payments (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Schedule of Future Minimum Rental Payments Including Imputed Interest [Table Text Block]	As of June 30, 2019 , minimum future payments, including imputed interest, for long-term operating leases under the scope of ASC 842 are as follows: Year Amount (in millions) 2019 $ 12.4 2020 $ 21.1 2021 $ 19.4 2022 $ 14.9 2023 $ 9.4 After 2023 $ 0.5 Less: Interest (1) $ (11.0 ) Present value of lease liabilities (2) $ 66.7 ____________________________ (1) Calculated using the estimated or stated interest rate for each lease. (2) Of the total present value of lease liabilities, $18.8 million was recorded in "Current operating lease liabilities" and $47.9 million was recorded in "Operating lease liabilities" on the Condensed Consolidated Balance Sheets.
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	As of December 31, 2018 , minimum future contractual payments for long-term operating leases under the scope of ASC 840 are as follows: Year Amount (in millions) 2019 $ 17.4 2020 $ 13.8 2021 $ 9.1 2022 $ 7.4 2023 $ 4.5 After 2023 $ —

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation Expense [Table Text Block]	Share-based compensation expense is generally recognized within "General and administrative" expense on the Condensed Consolidated Statements of Operations and is summarized in the table below. During the three and six months ended June 30, 2019 , the Company recorded an additional $1.3 million and $9.7 million , respectively, of share-based compensation expense related to the acceleration of vesting that occurred as part of the restructuring program, of which $1.5 million was recorded in "Net gain (loss) from asset sales, inclusive of restructuring costs" on the Condensed Consolidated Statement of Operations during the six months ended June 30, 2019 and the remaining $1.3 million and $8.2 million , respectively, is included in the table below. During the three and six months ended June 30, 2018 , the Company recorded an additional $1.2 million and $4.0 million , respectively of share-based compensation expense, related to the acceleration of vesting that occurred as part of the restructuring program, all of which is included in the table below. Refer to Note 9 – Restructuring for additional information. Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 (in millions) Stock options $ — $ 0.2 $ 0.3 $ 0.7 Restricted share awards 4.8 6.8 10.9 15.6 Performance share units 0.3 5.1 5.5 7.0 Restricted share units 0.1 0.1 0.2 0.1 Total share-based compensation expense $ 5.2 $ 12.2 $ 16.9 $ 23.4
Share-based Compensation, Stock Options, Activity [Table Text Block]	Stock option transactions under the terms of the LTSIP are summarized below: Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (per share) (in years) (in millions) Outstanding at December 31, 2018 2,098,933 $ 22.27 Cancelled (283,029 ) 30.90 Outstanding at June 30, 2019 1,815,904 $ 20.93 2.80 $ — Options Exercisable at June 30, 2019 1,761,139 $ 21.08 2.74 $ — Unvested Options at June 30, 2019 54,765 $ 15.92 4.69 $ —
Schedule of Share-based Compensation, Restricted Share Awards Activity [Table Text Block]	Transactions involving restricted share awards under the terms of the LTSIP and LTIP are summarized below: Restricted Share Awards Outstanding Weighted-Average Grant Date Fair Value (per share) Unvested balance at December 31, 2018 3,822,133 $ 10.76 Granted 2,217,794 7.98 Vested (2,261,323 ) 11.05 Forfeited (178,985 ) 9.23 Unvested balance at June 30, 2019 3,599,619 $ 8.94 Transactions involving restricted share units under the terms of the LTSIP and LTIP are summarized below: Restricted Share Units Outstanding Weighted-Average Grant Date Fair Value (per share) Unvested balance at December 31, 2018 42,675 $ 10.47 Granted 37,224 7.93 Vested and paid (36,392 ) 10.67 Unvested balance at June 30, 2019 43,507 $ 8.16
Schedule of Other Share-based Compensation, PSUs & RSUs [Table Text Block]	Transactions involving performance share units under the terms of the CIP are summarized below: Performance Share Units Outstanding Weighted-Average Grant Date Fair Value (per share) Unvested balance at December 31, 2018 1,559,312 $ 11.47 Granted 589,412 7.93 Vested and paid (1,117,848 ) 10.73 Unvested balance at June 30, 2019 1,030,876 $ 9.63

Employee Benefits (Tables)

Employee Benefits (Tables)	6 Months Ended
	Jun. 30, 2019
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs [Table Text Block]	The following table sets forth the Company's net periodic benefit costs related to its Pension Plan, SERP and Medical Plan: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Pension Plan and SERP benefits (in millions) Service cost $ — $ 0.2 $ 0.1 $ 0.4 Interest cost 1.2 1.1 2.4 2.2 Expected return on plan assets (1.4 ) (1.5 ) (2.9 ) (2.9 ) Amortization of prior service costs (1) 0.1 0.2 0.2 0.4 Amortization of actuarial losses (1) — 0.3 0.1 0.6 Curtailment (gain) loss (2) 0.1 — 0.4 — Periodic expense $ — $ 0.3 $ 0.3 $ 0.7 Medical Plan benefits Interest cost $ 0.1 $ 0.1 $ 0.1 $ 0.1 Amortization of prior service costs (1) — — — (0.1 ) Curtailment (gain) loss (2) — — (0.8 ) — Periodic expense $ 0.1 $ 0.1 $ (0.7 ) $ — ____________________________ (1) Amortization of prior service costs and actuarial losses out of accumulated other comprehensive income (loss) are recognized on the Condensed Consolidated Statements of Operations within "Interest and other income (expense)". (2) A curtailment is recognized when there is a significant reduction in, or an elimination of, defined benefit accruals for current employees' future services. The net curtailment gain between the SERP and Medical Plan of $0.4 million is related to the Haynesville Divestiture and corporate restructuring activities. Of the $0.4 million curtailment gain recognized, $0.2 million was recognized on the Condensed Consolidated Statements of Operations within "Interest and other income (expense)" and $0.2 million was recognized on the Condensed Consolidated Statements of Operations within "Net gain (loss) from asset sales, inclusive of restructuring costs" for the six months ended June 30, 2019 .

Basis of Presentation ImpaIrmen

Basis of Presentation ImpaIrment of Long Lived Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment	$ 0	$ 403.7	$ 5	$ 404.4
Impairment of Leasehold				1.6
Uinta Basin Divestiture [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment				$ 402.8

Basis of Presentation Restric_2

Basis of Presentation Restricted Cash (Details) - USD ($) $ in Millions		Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents		$ 97.1	$ 0	$ 0
Restricted cash(1)	[1]	29.2		26.1
Total cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows		$ 126.3	$ 28.1	$ 26.1	$ 23.4
[1]	As of June 30, 2019 and 2018

Revenue Disaggregated Revenue (

Revenue Disaggregated Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue from Contract with Customer, Including Assessed Tax	$ 296.2	$ 532.4	$ 576.8	$ 961.3
Oil and Condensate [Member] | As reported [Member] | Williston Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	107.5	207.6	217.4	368.1
Oil and Condensate [Member] | As reported [Member] | Uinta Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax		9.5		17.9
Oil and Condensate [Member] | As reported [Member] | Other Northern [Member]
Revenue from Contract with Customer, Including Assessed Tax	0.5	0.9	0.9	2.8
Oil and Condensate [Member] | As reported [Member] | Permian Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	177.6	190.3	316.8	320.1
Oil and Condensate [Member] | As reported [Member] | Haynesville/Cotton Valley [Member]
Revenue from Contract with Customer, Including Assessed Tax		0.2		0.6
Oil and Condensate [Member] | As reported [Member] | Other Southern [Member]
Revenue from Contract with Customer, Including Assessed Tax	0.1	0	0.1	(0.3)
Oil and Condensate [Member] | As reported [Member] | Total [Member]
Revenue from Contract with Customer, Including Assessed Tax	285.7	408.5	535.2	709.2
Natural Gas [Member] | As reported [Member] | Williston Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	7.5	8.4	20	18.2
Natural Gas [Member] | As reported [Member] | Uinta Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax		7.9		18
Natural Gas [Member] | As reported [Member] | Other Northern [Member]
Revenue from Contract with Customer, Including Assessed Tax	0.1	0.2	0.3	1.2
Natural Gas [Member] | As reported [Member] | Permian Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	(0.6)	3.2	4	7.8
Natural Gas [Member] | As reported [Member] | Haynesville/Cotton Valley [Member]
Revenue from Contract with Customer, Including Assessed Tax		77.9		154.3
Natural Gas [Member] | As reported [Member] | Other Southern [Member]
Revenue from Contract with Customer, Including Assessed Tax	0.3	0.2	6	0.3
Natural Gas [Member] | As reported [Member] | Total [Member]
Revenue from Contract with Customer, Including Assessed Tax	7.3	97.8	30.3	199.8
Natural Gas, Midstream [Member] | As reported [Member] | Williston Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	5.8	14.7	13.2	26.5
Natural Gas, Midstream [Member] | As reported [Member] | Uinta Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax		1.7		3.4
Natural Gas, Midstream [Member] | As reported [Member] | Other Northern [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	0.1	0	(0.1)
Natural Gas, Midstream [Member] | As reported [Member] | Permian Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	8.5	9.9	18	16.4
Natural Gas, Midstream [Member] | As reported [Member] | Haynesville/Cotton Valley [Member]
Revenue from Contract with Customer, Including Assessed Tax		0		0
Natural Gas, Midstream [Member] | As reported [Member] | Other Southern [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Natural Gas, Midstream [Member] | As reported [Member] | Total [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	14.3	26.4	31.2	46.2
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | As reported [Member] | Williston Basin [Member]
Cost of Goods and Services Sold	(8.9)	(10.7)	(19)	(20.6)
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | As reported [Member] | Uinta Basin [Member]
Cost of Goods and Services Sold		0		0
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | As reported [Member] | Other Northern [Member]
Cost of Goods and Services Sold	0	0	0	0
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | As reported [Member] | Permian Basin [Member]
Cost of Goods and Services Sold	(3.8)	(1.7)	(7.5)	(4.5)
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | As reported [Member] | Haynesville/Cotton Valley [Member]
Cost of Goods and Services Sold		0		0
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | As reported [Member] | Other Southern [Member]
Cost of Goods and Services Sold	0	0	0	0
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | As reported [Member] | Total [Member]
Cost of Goods and Services Sold	(12.7)	(12.4)	(26.5)	(25.1)
Oil and Gas, Exploration and Production [Member]
Revenue from Contract with Customer, Including Assessed Tax	294.6	520.3	570.2	930.1
Oil and Gas, Exploration and Production [Member] | As reported [Member] | Williston Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	111.9	220	231.6	392.2
Oil and Gas, Exploration and Production [Member] | As reported [Member] | Uinta Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax		19.1		39.3
Oil and Gas, Exploration and Production [Member] | As reported [Member] | Other Northern [Member]
Revenue from Contract with Customer, Including Assessed Tax	0.6	1.2	1.2	3.9
Oil and Gas, Exploration and Production [Member] | As reported [Member] | Permian Basin [Member]
Revenue from Contract with Customer, Including Assessed Tax	181.7	201.7	331.3	339.8
Oil and Gas, Exploration and Production [Member] | As reported [Member] | Haynesville/Cotton Valley [Member]
Revenue from Contract with Customer, Including Assessed Tax		78.1		154.9
Oil and Gas, Exploration and Production [Member] | As reported [Member] | Other Southern [Member]
Revenue from Contract with Customer, Including Assessed Tax	0.4	0.2	6.1	0
Oil and Gas, Exploration and Production [Member] | As reported [Member] | Total [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 294.6	$ 520.3	$ 570.2	$ 930.1

Acquisitions & Divestitures Acq

Acquisitions & Divestitures Acquisitions (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment	$ 666.7	$ 48.8
Payments to acquire oil and gas property	$ 1.8	45.1
Permian Basin [Member]
Business Acquisition [Line Items]
Payments to acquire oil and gas property		$ 37.5

Acquisitions & Divestitures Uin

Acquisitions & Divestitures Uinta Basin (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2018	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment			$ 666.7	$ 48.8
Noncurrent assets held for sale	$ 0		0			$ 692.7
Gain (Loss) on Disposition of Oil and Gas Property	17.8	$ (3.9)	4.6	(0.4)
Impairment	0	403.7	5	404.4
Uinta Basin Divestiture [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment					$ 153
Impairment				402.8
Uinta Basin [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Results of Operations, Loss before Income Taxes	$ 0.3	$ 409.9	$ 0.2	$ 414.9

Acquisitions & Divestitures Pin

Acquisitions & Divestitures Pinedale Divestiture (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2017
Divestitures [Line Items]
Proceeds from disposition of assets			$ 666.7	$ 48.8
Net gain (loss) from asset sales, inclusive of restructuring costs	$ 17.8	$ (3.9)	4.6	(0.4)
Income (loss) before income taxes	78.5	$ (442.2)	(150.2)	$ (509.7)
Pinedale Divestiture [Member]
Divestitures [Line Items]
Proceeds from disposition of assets					$ 718.2
Net gain (loss) from asset sales, inclusive of restructuring costs			0.8
Minimum volume commitment			45
Minimum volume commitment remaining	$ 2		$ 2

Acquisitions & Divestitures Oth

Acquisitions & Divestitures Other Divestitures (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Divestitures [Line Items]
Proceeds from disposition of assets			$ 666.7	$ 48.8
Net gain (loss) from asset sales, inclusive of restructuring costs	$ 17.8	$ (3.9)	4.6	(0.4)
Non-core properties Divestitures [Member]
Divestitures [Line Items]
Proceeds from disposition of assets			39.7	48.8
Net gain (loss) from asset sales, inclusive of restructuring costs			$ 5.5	$ 0.7

Acquisitions & Divestitures Hay

Acquisitions & Divestitures Haynesville Divestiture (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Noncurrent assets held for sale	$ 0	$ 692.7		$ 0
Payments to acquire oil and gas property				1.8	$ 45.1
Proceeds from Sale of Oil and Gas Property and Equipment				666.7	48.8
Gain (Loss) on Disposition of Oil and Gas Property	17.8		$ (3.9)	4.6	(0.4)
Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Payments to acquire oil and gas property		634.2
Proceeds from Sale of Oil and Gas Property and Equipment				627.1
Gain (Loss) on Disposition of Oil and Gas Property	14.3	3		0.7
Results of Operations, Loss before Income Taxes	$ 14.4		$ 7.4	3.3	$ 19.7
Restructuring Charges				(1.4)
Property, Plant and Equipment [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		683.7
Other Noncurrent Assets [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		7.8
Noncurrent Assets Held for Sale [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		692.7
Other Current Liabilities [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		3.4
Asset Retirement Obligations, Current [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		0.7
Asset Retirement Obligations, Long Term [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		56.9
Derivative Financial Instruments, Liabilities [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		0.3
Other Noncurrent Liabilities [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		61.3
Other Current Assets [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Noncurrent assets held for sale		$ 1.2
Total incurred to date [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Gain (Loss) on Disposition of Oil and Gas Property				(3.7)
Accounts Receivable [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment				9.5
Accounts Payable [Member] | Haynesville Divestiture [Member]
Business Acquisition [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment				$ (2.4)

Earnings Per Share Components o

Earnings Per Share Components of Basic and Diluted Shares Used In EPS Calculation (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	0	0.1	0	0.1
Weighted-average basic common shares outstanding	238	237	237.5	238.9
Potential number of shares issuable upon exercise of in-the-money stock options under the Long-Term Stock Incentive Plan	0	0	0	0
Average diluted common shares outstanding	238	237	237.5	238.9

Earnings Per Share Earnings per

Earnings Per Share Earnings per share (non-printing) (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Anti-dilutive shares	0	0.1	0	0.1

Asset Retirement Obligations Co

Asset Retirement Obligations Consolidated Balance Sheet Line Items of ARO Liability (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligations, current liability	$ 6.8		$ 5.1
Asset retirement obligations	94.6		96.9
Other long-term liabilities held for sale	0		57.6
Total ARO Liability	$ 101.4	$ 159.6	$ 159.6

Asset Retirement Obligations As

Asset Retirement Obligations Asset Retirement Obligations ARO Rollforward (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)
Divestitures [Line Items]
ARO liability at January 1, 2019	$ 159.6
Accretion	3.1
Additions	0.4
Revisions	(0.3)
Liabilities related to assets sold(1)	(60.7)
Liabilities settled	(0.7)
ARO Liability at June 30, 2019	101.4
Haynesville Divestiture [Member]
Divestitures [Line Items]
Liabilities related to assets sold(1)	$ 57.6

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Millions		Jun. 30, 2019	Dec. 31, 2018
Financial Assets
Derivative Asset, Netting Adjustments	[1]	$ 0	$ (0.4)
Derivative Asset, Net		17.9	123.2
Financial liabilities
Derivative Liability, Netting Adjustments	[1]	0	(0.4)
Derivative Liability, Net		18.5	0.7
Level 1 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0	0
Financial liabilities
Derivative Liability, Fair Value, Gross		0	0
Fair Value, Inputs, Level 2 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		17.9	123.6
Financial liabilities
Derivative Liability, Fair Value, Gross		18.5	1.1
Level 3 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0	0
Financial liabilities
Derivative Liability, Fair Value, Gross		0	0
Noncurrent Assets Held for Sale [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross			0.3
Long-term [Member]
Financial Assets
Derivative Asset, Netting Adjustments	[1]	0	0
Derivative Asset, Net		15.2	35.4
Financial liabilities
Derivative Liability, Netting Adjustments	[1]	0	0
Derivative Liability, Net		0.9	0.7
Long-term [Member] | Level 1 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0	0
Financial liabilities
Derivative Liability, Fair Value, Gross		0	0
Long-term [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		15.2	35.4
Financial liabilities
Derivative Liability, Fair Value, Gross		0.9	0.7
Long-term [Member] | Level 3 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0	0
Financial liabilities
Derivative Liability, Fair Value, Gross		0	0
Short-term [Member]
Financial Assets
Derivative Asset, Netting Adjustments	[1]	0	(0.4)
Derivative Asset, Net		2.7	87.8
Financial liabilities
Derivative Liability, Netting Adjustments	[1]	0	(0.4)
Derivative Liability, Net		17.6	0
Short-term [Member] | Level 1 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0	0
Financial liabilities
Derivative Liability, Fair Value, Gross		0	0
Short-term [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		2.7	88.2
Financial liabilities
Derivative Liability, Fair Value, Gross		17.6	0.4
Short-term [Member] | Level 3 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0	0
Financial liabilities
Derivative Liability, Fair Value, Gross		$ 0	$ 0
[1]	The Company nets its derivative contract assets and liabilities outstanding with the same counterparty on the Condensed Consolidated Balance Sheets for the contracts that contain netting provisions. Refer to Note 7 – Derivative Contracts for additional information regarding the Company's derivative contracts.

Fair Value Measurements Fair _2

Fair Value Measurements Fair Value and Related Carrying Amount of Certain Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 97.1	$ 0	$ 0
Checks outstanding in excess of cash balances	5.3	14.6
Debt, Long-term and Short-term, Combined Amount	2,079.8	2,507.1
Long-term debt	2,028.1	2,507.1
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	97.1	0
Checks outstanding in excess of cash balances	5.3	14.6
Long-term debt, fair value	$ 2,042.5	$ 2,350.5

Fair Value Measurements Narrati

Fair Value Measurements Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment	$ 0	$ 403.7	$ 5	$ 404.4
Proved Property [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of Oil and Gas Properties			$ 5	$ 397.6

Derivative Contracts (Narrative

Derivative Contracts (Narrative) (Details)	6 Months Ended
	Jun. 30, 2019
Derivative [Line Items]
Maximum Forecasted Production Covered By Derivatives	100.00%
Minimum [Member]
Derivative [Line Items]
Expected Annual Production Covered By Derivatives	50.00%
Maximum [Member]
Derivative [Line Items]
Expected Annual Production Covered By Derivatives	75.00%

Derivative Contracts Schedule O

Derivative Contracts Schedule Of Commodity Derivative Contracts (Details) MMBTU in Millions	6 Months Ended
	Jun. 30, 2019USD ($)MMBTU$ / MMBTU	Dec. 31, 2018USD ($)
Oil Swaps [Member] | Year 2019 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	6.6
Average Swap Price per Unit | $	$ 55.24
Oil Swaps [Member] | Year 2019 [Member] | Argus WTI Midland [Member]
Derivative [Line Items]
Derivative Volumes	0.7
Average Swap Price per Unit | $	$ 60
Oil Swaps [Member] | Year 2019 [Member] | ICE Brent [Member]
Derivative [Line Items]
Derivative Volumes	0.9
Average Swap Price per Unit | $	$ 66.73
Oil Swaps [Member] | Year 2019 [Member] | Argus WTI Houston [Member]
Derivative [Line Items]
Derivative Volumes	0.2
Average Swap Price per Unit | $	$ 65.70
Oil Swaps [Member] | Year 2020 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	6.2
Average Swap Price per Unit | $	$ 60.07
Oil Basis Swaps [Member] | Year 2019 [Member] | NYMEX WTI less Argus WTI Midland [Member]
Derivative [Line Items]
Derivative Volumes	3.3
Weighted-Average Differential | $ / MMBTU	(2.22)
Oil Basis Swaps [Member] | Year 2019 [Member] | NYMEX WTI less Argus WTI Houston [Member]
Derivative [Line Items]
Derivative Volumes	0.9
Weighted-Average Differential | $ / MMBTU	3.69
Oil Basis Swaps [Member] | Year 2020 [Member] | NYMEX WTI less Argus WTI Midland [Member]
Derivative [Line Items]
Derivative Volumes	4.4
Weighted-Average Differential | $ / MMBTU	(0.02)
Oil Basis Swaps [Member] | Year 2020 [Member] | NYMEX WTI less Argus WTI Houston [Member]
Derivative [Line Items]
Derivative Volumes	0.4
Weighted-Average Differential | $ / MMBTU	3.75
Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross | $	$ 17,900,000	$ 123,600,000
Fair Value, Inputs, Level 2 [Member] | Noncurrent Assets Held for Sale [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross | $		$ 300,000

Derivative Contracts Schedule_2

Derivative Contracts Schedule of Derivatives Financial Statement Presentation (Details) - Fair Value, Inputs, Level 2 [Member] - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative Asset, Fair Value, Gross	$ 17.9	$ 123.6
Derivative Liability, Fair Value, Gross	18.5	1.1
Short-term [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross	2.7	88.2
Derivative Liability, Fair Value, Gross	17.6	0.4
Long-term [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross	15.2	35.4
Derivative Liability, Fair Value, Gross	0.9	0.7
Fair Value, Measurements, Recurring [Member] | Commodity Contract [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross	17.9	123.6
Derivative Liability, Fair Value, Gross	18.5	1.1
Fair Value, Measurements, Recurring [Member] | Commodity Contract [Member] | Short-term [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross	2.7	88.2
Derivative Liability, Fair Value, Gross	17.6	0.4
Fair Value, Measurements, Recurring [Member] | Commodity Contract [Member] | Long-term [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross	15.2	35.4
Derivative Liability, Fair Value, Gross	$ 0.9	$ 0.7

Derivative Contracts Gain (Loss

Derivative Contracts Gain (Loss) in Statement of Financial Performance (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative [Line Items]
Realized gain (loss) on commodity derivative contracts not designated as hedging instruments	$ (16)	$ (45.5)	$ (21.9)	$ (88.7)
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments	38.5	(79.1)	(143.2)	(132.3)
Oil derivative contracts [Member] | Production [Member]
Derivative [Line Items]
Realized gain (loss) on commodity derivative contracts not designated as hedging instruments	(16)	(52)	(19)	(96.3)
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments	54.5	(20.6)	(122.8)	(27.5)
Gas derivative contracts [Member] | Production [Member]
Derivative [Line Items]
Realized gain (loss) on commodity derivative contracts not designated as hedging instruments	0	6.4	(2.9)	7.3
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments	0	(13)	(0.3)	(15.8)
Gas derivative contracts [Member] | Storage [Member]
Derivative [Line Items]
Realized gain (loss) on commodity derivative contracts not designated as hedging instruments	0	0.1	0	0.3
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments	0	0	0	(0.3)
Total [Member]
Derivative [Line Items]
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments	54.5	(33.6)	(123.1)	(43.6)
Realized and Unrealized Gain (Loss) on Commodity Derivative Contracts Not Designated as Hedging Instruments	38.5	(79.1)	(145)	(132.3)
Uinta Basin Divestiture [Member]
Derivative [Line Items]
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments	0		1.8
Uinta Basin Divestiture [Member] | Gas derivative contracts [Member] | Production [Member]
Derivative [Line Items]
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments	$ 0		$ 1.8
Pinedale Divestiture [Member]
Derivative [Line Items]
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments		0		0
Pinedale Divestiture [Member] | Gas derivative contracts [Member] | Production [Member]
Derivative [Line Items]
Unrealized gain (loss) on commodity derivative contracts not designated as hedging instruments		$ 0		$ 0

Leases (Details)

Leases (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Lessor, Lease, Description [Line Items]
Lease, Cost	$ 11	$ 21.9
Operating Lease, Weighted Average Remaining Lease Term	3 years 7 months 6 days	3 years 7 months 6 days
Operating Lease, Weighted Average Discount Rate, Percent	7.70%	7.70%
Property, Plant and Equipment [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	$ 4.1	$ 8.8
Lease Operating Expense [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	3	6.1
Gathering and other expense [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	2.3	3.8
General and Administrative Expense [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	$ 1.6	$ 3.2

Restructuring Costs Restructu_2

Restructuring Costs Restructuring Expense Table (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Nonoperating Income (Expense) [Member]
Total restructuring costs	$ 0.1		$ (0.2)
Other Expense [Member]
Total restructuring costs		$ 0		$ 0
Termination Benefits [Member]
Costs recognized period from inception to June 30, 2019(1)	38.9		38.9
Total remaining costs expected to be incurred			0
Office lease Termination Costs [Member]
Costs recognized period from inception to June 30, 2019(1)	1.6		1.6
Total remaining costs expected to be incurred			0
Accelerated Share Based Compensation [Member]
Costs recognized period from inception to June 30, 2019(1)	21		21
Total remaining costs expected to be incurred			0
Retention Expense [Member]
Costs recognized period from inception to June 30, 2019(1)	29.7		29.7
Total remaining costs expected to be incurred			10.1
Pension curtailment [Member]
Costs recognized period from inception to June 30, 2019(1)	(0.2)		(0.2)
Total remaining costs expected to be incurred			0
Total [Member]
Termination benefits	(0.1)	3.6	6.7	7
Office lease termination costs	0	0.3	0.6	0.3
Accelerated share-based compensation(1)	1.3	1.2	9.7	4
Retention expense (including share-based compensation)	4.8	6.3	10.9	8
Pension and Medical Plan curtailment	0.1		(0.4)
Total restructuring costs	6.1	11.4	27.5	19.3
Costs recognized period from inception to June 30, 2019(1)	91		91
Total remaining costs expected to be incurred			10.1
General and Administrative Expense [Member]
Termination benefits	(0.1)	1.7	6.6	5.1
Office lease termination costs	0	0.3	0.6	0.3
Accelerated share-based compensation(1)	1.3	1.2	8.2	4
Retention expense (including share-based compensation)	4.8	6.3	10.9	8
Pension and Medical Plan curtailment	0		0
Total restructuring costs	6	9.5	26.3	17.4
Net gain (loss) from asset sales [Member]
Termination benefits	0	1.9	0.1	1.9
Office lease termination costs	0	0	0	0
Accelerated share-based compensation(1)	0	0	1.5	0
Retention expense (including share-based compensation)	0	0	0	0
Pension and Medical Plan curtailment	0		(0.2)
Total restructuring costs	0	1.9	1.4	1.9
Interest and other income (expense) [Member]
Termination benefits	0	0	0	0
Office lease termination costs	0	0	0	0
Accelerated share-based compensation(1)	0	0	0	0
Retention expense (including share-based compensation)	0	$ 0	0	$ 0
Pension and Medical Plan curtailment	0.1		(0.2)
Net gain (loss) from asset sales [Member] | Total [Member]
Pension and Medical Plan curtailment			(0.5)
Total incurred to date [Member]
Accelerated share-based compensation(1)	$ 2.8		$ 21.7

Restructuring Costs Restructu_3

Restructuring Costs Restructuring Liability (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Liability	$ 2.3	$ 19.5
Costs incurred and charged to expense	6.7
Costs paid or otherwise settled	(23.9)
Office lease Termination Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Liability	0	0
Costs incurred and charged to expense	0.6
Costs paid or otherwise settled	(0.6)
Accelerated Share Based Compensation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Liability	0	0
Costs incurred and charged to expense	9.7
Costs paid or otherwise settled	(9.7)
Retention Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Liability	5.8	10.8
Costs incurred and charged to expense	10.9
Costs paid or otherwise settled	(15.9)
Pension curtailment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Liability	0	0
Costs incurred and charged to expense	(0.4)
Costs paid or otherwise settled	0.4
Total [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Liability	8.1	$ 30.3
Costs incurred and charged to expense	27.5
Costs paid or otherwise settled	$ (49.7)

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt Maturity Period	5 years
Long-term Debt, Weighted Average Interest Rate, at Point in Time	4.73%
Principal amount of senior notes outstanding	$ 2,099.3
Senior Notes, stated interest rate, minimum (in hundredths)	5.25%
Senior Notes, stated interest rate, maximim (in hundredths)	6.875%
Revolving Credit Facility due 2019 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 0	$ 430
Maturity date of long-term debt	Sep. 1, 2022
Borrowing capacity	$ 1,250
Letters of credit outstanding	2.9	0.3
6.80% Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 51.7	51.7
Long-term debt, interest rate (in hundredths)	6.80%
Maturity date of long-term debt	Mar. 1, 2020
6.875% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 397.6	397.6
Long-term debt, interest rate (in hundredths)	6.875%
Maturity date of long-term debt	Mar. 1, 2021
5.375% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500	$ 500
Long-term debt, interest rate (in hundredths)	5.375%
Maturity date of long-term debt	Oct. 1, 2022
Senior Notes Due 2023 [Member]
Debt Instrument [Line Items]
Long-term debt, interest rate (in hundredths)	5.25%
Maturity date of long-term debt	May 1, 2023
Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Maturity date of long-term debt	Mar. 1, 2026

Debt Schedule of Debt Instrumen

Debt Schedule of Debt Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Less unamortized discount	$ (19.5)	$ (22.2)
Debt, Long-term and Short-term, Combined Amount	2,079.8	2,507.1
Long-term debt	2,028.1	2,507.1
Total long-term debt outstanding	2,028.1	2,507.1
Less: current portion of long-term debt	(51.7)	0
Revolving Credit Facility due 2019 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	0	430
6.80% Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	51.7	51.7
6.875% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	397.6	397.6
5.375% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	500	500
5.25% Senior Notes Due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	650	650
5.625% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500	$ 500

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 12.4	$ 17.4
Operating Leases, Future Minimum Payments, Due in Two Years	21.1	13.8
Operating Leases, Future Minimum Payments, Due in Three Years	19.4	9.1
Operating Leases, Future Minimum Payments, Due in Four Years	14.9	7.4
Operating Leases, Future Minimum Payments, Due in Five Years	9.4	4.5
Operating Leases, Future Minimum Payments, Due Thereafter	$ 0.5	$ 0

Commitments and Contingencies_2

Commitments and Contingencies Minimum Lease Payments Under ASC 842 (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Current operating lease lease liabilities	$ 18.8	$ 0
Operating lease liabilities	47.9	0
Operating Leases, Future Minimum Payments Due, Next Twelve Months	12.4	17.4
Operating Leases, Future Minimum Payments, Due in Two Years	21.1	13.8
Operating Leases, Future Minimum Payments, Due in Three Years	19.4	9.1
Operating Leases, Future Minimum Payments, Due in Four Years	14.9	7.4
Operating Leases, Future Minimum Payments, Due in Five Years	9.4	4.5
Operating Leases, Future Minimum Payments, Due Thereafter	0.5	$ 0
Lease operating expense	(11)
Operating Lease, Liability	$ 66.7

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	10
Shares available for future grants	8.3
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 0.1
Weighted average vesting period	9 months 10 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Share Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, grants	$ 7.98	$ 9.55
Unrecognized compensation costs	$ 18.8
Weighted average vesting period	2 years 3 months 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Total fair value of stock that vested during the period	$ 25	$ 24.6
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Share-based Liabilities Paid	$ 11.4	$ 2
Weighted average grant date fair value, grants	$ 7.93	$ 9.55
Unrecognized compensation costs	$ 7.2
Weighted average vesting period	2 years 3 months 29 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Share Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, grants	$ 7.93	$ 9.55
Unrecognized compensation costs	$ 0.2
Weighted average vesting period	1 year 7 months 20 days

Share-Based Compensation Share-

Share-Based Compensation Share-based compensation expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	$ 5.2	$ 12.2	$ 16.9	$ 23.4
Stock Options [Member]
Share-based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	0	0.2	0.3	0.7
Performance Share Units [Member]
Share-based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	0.3	5.1	5.5	7
Restricted Shares [Member]
Share-based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	4.8	6.8	10.9	15.6
Restricted Share Units (RSUs) [Member]
Share-based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	0.1	0.1	0.2	0.1
Net gain (loss) from asset sales [Member]
Share-based Compensation Expense [Line Items]
Accelerated Share Based Compensation	0	0	1.5	0
General and Administrative Expense [Member]
Share-based Compensation Expense [Line Items]
Accelerated Share Based Compensation	1.3	1.2	8.2	4
Total [Member]
Share-based Compensation Expense [Line Items]
Accelerated Share Based Compensation	$ 1.3	$ 1.2	$ 9.7	$ 4

Share-Based Compensation Schedu

Share-Based Compensation Schedule Of Stock Option Transactions (Details) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of period | shares	2,098,933
Options canceled | shares	(283,029)
Outstanding at end of period | shares	1,815,904
Options exercisable, shares | shares	1,761,139
Unvested options, shares | shares	54,765
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average exercise price, beginning of year | $ / shares	$ 22.27
Weighted average exercise price, canceled in period | $ / shares	30.90
Weighted average exercise price, end of year | $ / shares	20.93
Options exercisable, weighted average exercise price | $ / shares	21.08
Unvested options, weighted average exercise price | $ / shares	$ 15.92
Weighted average remaining contractual term, options outstanding	2 years 9 months 18 days
Weighted average remaining contractual term, options exercisable	2 years 8 months 26 days
Weighted average remaining contractual term, options unvested	4 years 8 months 8 days
Aggregate intrinsic value, options outstanding | $	$ 0
Aggregate intrinsic value, options exercisable | $	0
Aggregate intrinsic value, options unvested | $	$ 0
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years

Share-Based Compensation Sche_2

Share-Based Compensation Schedule of Restricted Share Awards Transactions (Details) - Restricted Share Awards [Member] - $ / shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested balance at beginning of period	3,822,133
Shares granted	2,217,794
Shares vested	(2,261,323)
Shares forfeited	(178,985)
Unvested balance at end of period	3,599,619
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Weighted average grant date fair value, beginning of period	$ 10.76
Weighted average grant date fair value, grants	7.98	$ 9.55
Weighted average grant date fair value, vested	11.05
Weighted average grant date fair value, forfeited	9.23
Weighted average grant date fair value, end of period	$ 8.94

Share-Based Compensation Sche_3

Share-Based Compensation Schedule Of Performance Share Unit Transactions (Details) - Performance Share Units [Member] - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Share-based Liabilities Paid	$ 11.4	$ 2
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested balance at beginning of period	1,559,312
Shares granted	589,412
Shares vested	(1,117,848)
Unvested balance at end of period	1,030,876
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Weighted average grant date fair value, beginning of period	$ 11.47
Weighted average grant date fair value, grants	7.93	$ 9.55
Weighted average grant date fair value, vested	10.73
Weighted average grant date fair value, end of period	$ 9.63

Share-Based Compensation Sche_4

Share-Based Compensation Schedule of Restricted Share Unit Transactions (Details) - Restricted Share Units (RSUs) [Member] - $ / shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Unvested balance at beginning of period	42,675
Shares granted	37,224
Shares vested and paid	(36,392)
Unvested balance at end of period	43,507
Weighted average grant date fair value, beginning of period	$ 10.47
Weighted average grant date fair value, grants	7.93	$ 9.55
Weighted average grant date fair value, vested	10.67
Weighted average grant date fair value, end of period	$ 8.16

Employee Benefits (Narrative) (

Employee Benefits (Narrative) (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by Employer		$ 5
SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by Employer		0.2
Estimated Future Employer Contributions in Current Fiscal Year	$ 0.3	0.3
Medical Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by Employer		0.1
Estimated Future Employer Contributions in Current Fiscal Year	0.2	0.2
401(k) Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by Employer		2.6
Estimated Future Employer Contributions in Current Fiscal Year	1.8	1.8
Pension Plan Discretionary Contribution [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	0.1	0.1
Total [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Medical Plan curtailment	0.1	(0.4)
Interest and other income (expense) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Medical Plan curtailment	0.1	(0.2)
Net gain (loss) from asset sales [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Medical Plan curtailment	$ 0	(0.2)
Restructuring Charges [Member] | Total [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Medical Plan curtailment		0.1
Net gain (loss) from asset sales [Member] | Total [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Medical Plan curtailment		$ (0.5)

Employee Benefits Schedule of N

Employee Benefits Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Pension Plan and SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		$ 0	$ 0.2	$ 0.1	$ 0.4
Interest cost		1.2	1.1	2.4	2.2
Expected return on plan assets		(1.4)	(1.5)	(2.9)	(2.9)
Amortization of prior service costs(1)	[1]	0.1	0.2	0.2	0.4
Amortization of actuarial losses(1)	[1]	0	0.3	0.1	0.6
Curtailment (gain) loss(2)	[2]	0.1	0	0.4	0
Periodic expense		0	0.3	0.3	0.7
Medical Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost		0.1	0.1	0.1	0.1
Amortization of prior service costs(1)	[1]	0	0	0	(0.1)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	[2]	0	0	(0.8)	0
Periodic expense		$ 0.1	$ 0.1	$ (0.7)	$ 0
[1]	Amortization of prior service costs and actuarial losses out of accumulated other comprehensive income (loss) are recognized on the Condensed Consolidated Statements of Operations within "Interest and other income (expense)".
[2]	A curtailment is recognized when there is a significant reduction in, or an elimination of, defined benefit accruals for current employees' future services. The net curtailment gain between the SERP and Medical Plan of $0.4 million is related to the Haynesville Divestiture and corporate restructuring activities. Of the $0.4 million curtailment gain recognized, $0.2 million was recognized on the Condensed Consolidated Statements of Operations within "Interest and other income (expense)" and $0.2 million was recognized on the Condensed Consolidated Statements of Operations within "Net gain (loss) from asset sales, inclusive of restructuring costs" for the six months ended June 30, 2019 .

Subsequent Event (Details)

Subsequent Event (Details)	6 Months Ended
	Jun. 30, 2019$ / shares
Subsequent Event [Line Items]
Dividends, Cash	$ 0.02