Dominion Questar 10-K 1 Mar 10 2009 FY Annual report Financial data

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (USD $)
In Millions, except Per Share data	12 Months Ended Dec. 31, 2009	12 Months Ended Dec. 31, 2008	12 Months Ended Dec. 31, 2007
REVENUES
Market Resources	$1,949	2297.2	1671.3
Questar Pipeline	170.1	173.7	127.7
Questar Gas	918.9	994.2	927.6
Total Revenues	3,038	3465.1	2726.6
OPERATING EXPENSES
Cost of natural gas and other products sold (excluding operating expenses shown separately)	716.2	1007.6	917.1
Operating and maintenance	369.2	367.6	293.9
General and administrative	183.8	166.1	170.1
Production and other taxes	105.3	164.9	101
Depreciation, depletion and amortization	706.2	494.4	369.1
Exploration	25	29.3	22
Abandonment and impairment	20.3	59.4	11.2
Total Operating Expenses	(2,126)	-2289.3	-1884.4
Net gain (loss) from asset sales	1.7	64.7	-0.9
OPERATING INCOME	913.7	1240.5	841.3
Interest and other income	16	26.7	14.3
Income from unconsolidated affiliates	6.5	2.3	8.9
Unrealized and realized gain (loss) on basis-only swaps	-189.6	-79.2	5.7
Interest expense	-128.7	-119.5	-72.2
INCOME BEFORE INCOME TAXES	617.9	1070.8	798
Income taxes	(222)	(378)	-290.6
NET INCOME	395.9	692.8	507.4
Net income attributable to noncontrolling interest	-2.6	(9)	0
NET INCOME ATTRIBUTABLE TO QUESTAR	393.3	683.8	507.4
EARNINGS PER COMMON SHARE ATTRIBUTABLE TO QUESTAR
Basic	2.26	3.96	2.95
Diluted	2.23	3.88	2.88
Weighted Average Number Of Common Shares Outstanding
Used in basic calculation	174.1	172.8	172
Used in diluted calculation	176.3	176.1	175.9
Dividends paid	0.505	0.4925	0.485

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)
In Millions	Dec. 31, 2009	Dec. 31, 2008
Current Assets
Cash and cash equivalents	30.8	23.9
Federal income taxes receivable	0	24.2
Accounts receivable, net	313.9	362.4
Unbilled-gas accounts receivable	86.9	95.8
Fair value of derivative contracts	128.2	431.3
Gas and oil storage	60.4	85.5
Materials and supplies	94.2	106.9
Regulatory assets	43.4	20.6
Prepaid expenses and other	37.8	34.4
Deferred income taxes - current	35.5	0
Total Current Assets	795.6	1,185
Net Property, Plant and Equipment - successful efforts method of accounting for gas and oil properties	7804.9	7,133
Investment in unconsolidated affiliates	72	68.4
Other Assets
Goodwill	69.9	70
Regulatory assets	23.5	26.3
Fair value of derivative contracts	61.2	106.3
Other noncurrent assets, net	35.1	41.7
Total Other Assets	189.7	244.3
Total Assets	8862.2	8630.7
Current Liabilities
Short-term debt	169	231.1
Accounts payables and accrued expenses	474	562.9
Production and other taxes	58.3	57.2
Customer advances	30.3	34.9
Federal income taxes payable	10.2	0
Interest payable	34.5	27.9
Fair value of derivative contracts	149.7	0.5
Purchase-gas adjustment	22.1	45.8
Deferred income taxes - current	9.8	130.6
Current portion of long-term debt	0	42
Total Current Liabilities	957.9	1132.9
Long-term debt, less current portion	2179.9	2078.9
Deferred income taxes	1508.2	1334.1
Asset retirement obligations	189.7	175.6
Defined benefit pension plan	166.4	205.2
Other postretirement benefits	40.5	44.8
Fair value of derivative contracts	140.6	69
Other long-term liabilities	121.9	142.7
EQUITY
Common stock - without par value; 510.0 million shares authorized; 174.6 million outstanding at Dec. 31, 2009, and 173.6 million outstanding at Dec. 31, 2008	454.8	451
Retained earnings	3077.7	2772.3
Accumulated other comprehensive income (loss)	-30.3	194.7
Total Common Shareholders' Equity	3502.2	3,418
Noncontrolling interest	54.9	29.5
Total Equity	3557.1	3447.5
Total Liabilities and Equity	8862.2	8630.7

PARENTHETICAL DATA TO THE CONSO

PARENTHETICAL DATA TO THE CONSOLIDATED BALANCE SHEETS (USD $)
Share data in Millions	Dec. 31, 2009	Dec. 31, 2008
EQUITY
Common Stock, No Par Value	0	0
Common Stock, Shares Authorized	510	350
Common Stock, Shares Outstanding	174.6	173.6

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY (USD $)
In Millions	12 Months Ended Dec. 31, 2009 Common Stock	12 Months Ended Dec. 31, 2008 Common Stock	12 Months Ended Dec. 31, 2007 Common Stock	Dec. 31, 2006 Common Stock	12 Months Ended Dec. 31, 2009 Retained Earnings	12 Months Ended Dec. 31, 2008 Retained Earnings	12 Months Ended Dec. 31, 2007 Retained Earnings	Dec. 31, 2006 Retained Earnings	12 Months Ended Dec. 31, 2009 Accumulated Other Comprehensive Income	12 Months Ended Dec. 31, 2008 Accumulated Other Comprehensive Income	12 Months Ended Dec. 31, 2007 Accumulated Other Comprehensive Income	Dec. 31, 2006 Accumulated Other Comprehensive Income	12 Months Ended Dec. 31, 2009 Noncontrolling Interest	12 Months Ended Dec. 31, 2008 Noncontrolling Interest	12 Months Ended Dec. 31, 2009 Comprehensive Income	12 Months Ended Dec. 31, 2008 Comprehensive Income	12 Months Ended Dec. 31, 2007 Comprehensive Income
Balance	$451	429.3	409.6		2772.3	2173.9	1750.2		194.7	-25.3	45.7		29.5
Balance, shares	173.6	172.8	171.8
Common stock issued (Value)	16.3	7.1	5.9
Common stock issued (Shares)	1.2	1.1	1.2
Common stock repurchased (Value)	-7.2	-15.3	-10.2
Common stock repurchased (Shares)	-0.2	-0.3	-0.2
Net income					393.3	683.8	507.4						2.6	9	395.9	692.8	507.4
Dividends paid					-87.9	-85.4	-83.7
Stock Issued During Period Value Share Based Compensation	22.7	16.7	12.9
Consolidation of noncontrolling interest														29.8
Noncontrolling interest equity adjustment	-28.5												28.5
Tax on equity adjustment	-3.1
Distribution to noncontrolling interest													-5.7	-9.3
Tax benefits from share-based compensation	3.6	13.2	11.1
Other comprehensive income
Change in unrealized fair value of derivatives									-405.1	494	-156.1				-405.1	494	-156.1
Change in unrecognized actuarial gain									44.5	-132.8	39.1				44.5	-132.8	39.1
Change in unrecognized prior-service costs									3.3	-13.9	3.1				3.3	-13.9	3.1
Income taxes									132.3	-127.3	42.9				132.3	-127.3	42.9
Total comprehensive income															170.9	912.8	436.4
Shares Issued	174.6	173.6	172.8	171.8
Balance	454.8	$451	429.3	409.6	3077.7	2772.3	2173.9	1750.2	-30.3	194.7	-25.3	45.7	54.9	29.5
Balance, shares	173.6	172.8	171.8

1_PARENTHETICAL DATA TO THE CON

PARENTHETICAL DATA TO THE CONSOLIDATED STATEMENTS OF EQUITY (USD $)
	12 Months Ended Dec. 31, 2009	12 Months Ended Dec. 31, 2008	12 Months Ended Dec. 31, 2007
Statement of Stockholders' Equity [Abstract]
Dividends paid	0.505	0.4925	0.485

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)
In Millions	12 Months Ended Dec. 31, 2009	12 Months Ended Dec. 31, 2008	12 Months Ended Dec. 31, 2007
OPERATING ACTIVITIES
Net income	395.9	692.8	507.4
Adjustments to reconcile net income to net cash provided from operating activities
Depreciation, depletion and amortization	714.6	502.1	375.8
Deferred income taxes	185.4	377.1	191.2
Abandonment and impairment	20.3	59.4	11.2
Share-based compensation	22.7	16.7	12.9
Dry exploratory well expense	4.7	9.7	12.3
Net (gain) loss from asset sales	-1.7	-64.7	0.9
(Income) from unconsolidated affiliates	-6.5	-2.3	-8.9
Distributions from unconsolidated affiliates	4.4	0.5	10.4
Unrealized mark-to-market gain (loss) on basis-only swaps	189.6	79.2	-5.7
Other operating	0.1	(2)	(1)
Changes in operating assets and liabilities
Accounts receivable	57.4	(47)	-7.6
Inventories	37.8	-77.4	26.7
Prepaid expenses	-3.4	(10)	3.3
Accounts payable and accrued expenses	-0.8	-6.1	-13.6
Federal income taxes	31.5	-17.6	3.4
Purchased-gas adjustments	-23.7	-12.3	16.2
Regulatory assets, liabilities and other	-24.5	-1.9	6.1
NET CASH PROVIDED BY OPERATING ACTIVITIES	1578.2	1496.2	1,141
INVESTING ACTIVITIES
Property, plant and equipment including dry exploratory well expense	-1496.7	-2437.2	-1383.5
Other investments	-1.5	-48.5	-14.8
Total capital expenditures	-1498.2	-2485.7	-1398.3
Cash used in disposition of assets	(2)	-3.7	-1.3
Proceeds from disposition of assets	16.1	130.7	14.5
NET CASH USED IN INVESTING ACTIVITIES	-1484.1	-2358.7	-1385.1
FINANCING ACTIVITIES
Common stock issued	16.3	7.1	5.9
Common stock repurchased	-7.2	-15.3	-10.2
Long-term debt issued, net of issuance costs	472.8	1741.7	100
Long-term debt repaid	(417)	-751.3	(10)
Change in short-term debt	-62.1	-29.5	220.6
Dividends paid	-87.9	-85.4	-83.7
Tax benefits from share-based compensation	3.6	13.2	11.1
Distribution to noncontrolling interest	-5.7	-9.3	0
Other financing	0	1	0
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	-87.2	872.2	233.7
Change in cash and cash equivalents	6.9	9.7	-10.4
Beginning cash and cash equivalents	23.9	14.2	24.6
Ending cash and cash equivalents	30.8	23.9	14.2
Supplemental Disclosure of Cash Paid During the Year for:
Interest	120.2	109.8	77.3
Income taxes	-3.6	13.8	89.5

Note 1 - Summary of Significant

Note 1 - Summary of Significant Accounting Policies
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Summary of Significant Accounting Policies	Note 1 - Summary of Significant Accounting Policies Nature of Business Questar Corporation (Questar or the Company) is a natural gas-focused energy company with five major lines of business - gas and oil exploration and production, midstream field services, energy marketing, interstate gas transportation, and retail gas distribution - which are conducted through its three principal subsidiaries: - Questar Market Resources, Inc. (Market Resources) is a subholding company that operates through four principal subsidiaries. Questar Exploration and Production Company (Questar E&P) acquires, explores for, develops and produces natural gas, oil and NGL. Wexpro Company (Wexpro) manages, develops and produces cost-of-service reserves for gas utility affiliate Questar Gas. Questar Gas Management Company (Gas Management) provides midstream field services including natural gas-gathering and processing services for affiliates and third parties. Questar Energy Trading Company (Energy Trading) markets equity and third-party natural gas and oil, provides risk-management services and owns and operates an underground gas-storage reservoir. - Questar Pipeline Company (Questar Pipeline) provides interstate natural gas transportation and storage and other energy services. - Questar Gas Company (Questar Gas) provides retail natural gas distribution services in Utah, Wyoming and Idaho. Accounting Standards References In July 2009 the Financial Accounting Standards Board (FASB) completed a revision of non-governmental U.S. generally accepted accounting principles (GAAP) into a single authoritative source and issued a codification of accounting rules and references. Authoritative standards included in the codification are designated by their Accounting Standards Codification (ASC) topical reference, and revised standards are designated as Accounting Standards Updates (ASU), with a year and assigned sequence number. The codification effort, while not creating or changing accounting rules, changed how users would cite accounting regulations. Citations in financial statements must identify the sections within the new codification. The codification is effective for interim and annual periods ending after September 15, 2009. The Company is complying with the new codification standards. Principles of Consolidation The consolidated financial statements contain the accounts of Questar and its majority-owned or controlled subsidiaries. The consolidated financial statements were prepared in accordance GAAP and with the instructions for annual reports on Form 10-K and Regulations S-X and S-K. Rendezvous Gas Services, an affiliate, was consolidated beginning in 2008 as a result of a step acquisition caused by disproportionate ownership. Gas Management's ownership interest increased from 50% to 78%. All significant intercompany accounts and transactions have been eliminated in consolidation. On January 1, 2009, Questar adopted "Noncontrolling Interests in Consolidated Financial Statements" (ASC 810-10-65-1) for the accounting, reporting and disclosure of noncontrolling interests. The new guidance requires that noncontrolling interest, previously known as minority interest, be cle

Note 2 - Earnings Per Share

Note 2 - Earnings Per Share
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Earnings Per Share	Note 2 - Earnings Per Share Earnings Per Share Basic earnings per share (EPS) is computed by dividing net income attributable to Questar 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. During the first quarter of 2009, the Company adopted the updated provisions of ASC 260, "Earnings Per Share." ASC 260 addresses whether instruments granted in share-based payment transactions are participating securities and therefore have a potential dilutive effect on EPS. The adoption was applied retrospectively and did not have a material effect on the Company's EPS calculations. A reconciliation of the components of basic and diluted shares used in the EPS calculation follows: Year Ended December 31, 200920082007 (in millions) Weighted-average basic common shares outstanding174.1 172.8 172.0 Potential number of shares issuable under the LTSIP2.2 3.3 3.9 Average diluted common shares outstanding176.3 176.1 175.9 In the past three years, Questar had the ability to issue shares under the terms of the Dividend Reinvestment and Stock Purchase Plan, Employee Investment Plan and Long-Term Stock Incentive Plan. Dividend Reinvestment and Stock Purchase Plan (Reinvestment Plan)The Reinvestment Plan allows parties interested in owning Questar common stock to reinvest dividends or invest additional funds in common stock. The Company can issue new shares or buy shares in the open market to meet shareholders' purchase requests. The Company issued 181,508 shares in 2009 and relied on open market purchases to meet 2008 and 2007 distributions. At December 31, 2009, 1,592,969 shares were reserved for future issuance. Long-Term Stock Incentive Plan Questar issues stock options and restricted shares to certain officers, directors, and employees under its LTSIP. Stock options for participants have terms ranging from five to ten years with a majority issued with a seven to ten-year term. Options held by employees generally vest in three or four equal, annual installments. Options granted to non-employee directors generally vest in one installment six months after grant. Restricted shares vest in equal installments over a specified number of years after the grant date with the majority vesting in three or four years. Nonvested restricted shares have voting and dividend rights; however, sale or transfer is restricted. Options and restricted shares issued prior to February 2006 vest on an accelerated basis in the event of a qualified termination, such as retirement, and have postretirement exercise periods. For a summary of LTSIP transactions see Note 13 - Share-Based Compensation.

Note 3 - Property, Plant and Eq

Note 3 - Property, Plant and Equipment
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Property, Plant and Equipment	Note 3 - Property, Plant and Equipment The details of property, plant and equipment and accumulated depreciation, depletion and amortization follow: December 31, 20092008 (in millions) Property, plant and equipmentMarket Resources Questar E&P Proved properties $ 5,721.5 $4,948.2 Unproved properties, not being depleted 389.6 193.2 Questar E&P total6,111.1 5,141.4 Wexpro1,022.5 911.5 Gas Management1,037.5 976.6 Energy Trading and other42.4 41.3 Market Resources total8,213.5 7,070.8 Questar Pipeline1,589.8 1,507.7 Questar Gas1,721.9 1,646.8 Corporate4.7 4.5 Total property, plant and equipment$11,529.9 $10,229.8 Accumulated depreciation, depletion and amortization Market Resources Questar E&P$1,890.9 $1,421.8 Wexpro 428.6 374.9 Gas Management198.7 159.3 Energy Trading and other10.1 8.4 Market Resources total2,528.3 1,964.4 Questar Pipeline502.5 471.4 Questar Gas690.4 657.3 Corporate3.8 3.7 Total accumulated depreciation, depletion and amortization3,725.0 3,096.8 Net Property, Plant and Equipment$7,804.9 $7,133.0 Questar E&P proved and unproved leaseholds had a net book value of $1,152.2 million at December 31, 2009, and $1,074.2 million in at December 31, 2008. In February 2008, Questar E&P acquired natural gas development properties in northwest Louisiana for an aggregate purchase price of $652.1 million effective January 1, 2008. The acquisition was accounted for as a purchase and, accordingly, the results of operations of the properties were included in net income from the closing date of the acquisition. After recording deferred income taxes of $13.1 million, the purchase price allocated to proved properties was $570.9 million and to unproved properties was $81.2 million. In conjunction with the acquisition of the Louisiana properties, the Company identified certain outside-operated producing properties and leaseholds in the Gulf Coast region of south Texas for divestiture. These properties contributed 2.8 Bcfe to Questar E&P net production in 2008. For income tax purposes, the Company structured a portion of the purchase of the Louisiana properties and the July 31, 2008, sale of the south Texas properties as a reverse like-kind exchange of property under Section 1031 of the Internal Revenue Code of 1986, as amended. The Company recognized a pre-tax gain on the sale of the Texas properties of approximately $61.2 million. Abandonment and impairment expense decreased $24.3 million or 54% in 2009 compared to 2008. Questar E&P abandonment and impairment expense increased $33.8 million or 313% in 2008 compared to 2007. Abandonment and impairment expense increased $29.9 million in the fourth quarter of 2008 compared with the same period of 2007. Lower year-end 2008 gas and oil prices triggered impairment testing of long-lived assets. Future cash flows using estimated forward-looking commodity prices were sufficient to recover the investment of a majority of the long-lived assets. A combination of poor production performance, higher production costs and negative reserve revisions resulted in the impairment of certain gas and oil assets in 2008. Questar Pipeline impairment expense amounted to $14.0 million in 2008. Questar Pipeline impaired the entir

Note 4 - Asset Retirement Oblig

Note 4 - Asset Retirement Obligations
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Asset Retirement Obligations	Note 4 - Asset Retirement Obligations Questar records asset retirement obligations (ARO) when there are legal obligations associated with the retirement of tangible long-lived assets. At Questar, ARO apply primarily to abandonment costs associated with gas and oil wells, production facilities and certain other properties. The fair value of retirement costs are estimated by Company personnel based on abandonment costs of similar properties available to field operations and depreciated over the life of the related assets. Revisions to ARO estimates result from changes in expected cash flows or material changes in estimated retirement costs. Income or expense resulting from the settlement of ARO liabilities is included in net gain or (loss) from asset sales on the Consolidated Statements of Income. The ARO liability is adjusted to present value each period through an accretion calculation using a credit-adjusted risk-free interest rate. Changes in ARO were as follows: 20092008 (in millions) ARO liability at January 1, $175.6 $149.1 Accretion 11.0 9.7 Liabilities incurred3.0 17.5 Revisions 2.4 1.5 Liabilities settled(2.3)(2.2)ARO liability at December 31, $189.7 $175.6 Wexpro collects from Questar Gas and deposits in trust certain funds related to estimated ARO costs. The funds are recorded in other noncurrent assets on the Consolidated Balance Sheets and used to satisfy retirement obligations as the properties are abandoned. The accounting treatment of reclamation activities associated with ARO for properties administered under the Wexpro Agreement is defined in a guideline letter between Wexpro and the Utah Division of Public Utilities and the staff of the PSCW.

Note 5 - Capitalized Explorator

Note 5 - Capitalized Exploratory Well Costs
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Capitalized Exploratory Well Costs	Note 5 - Capitalized Exploratory Well Costs Net changes in capitalized exploratory well costs are presented in the table below and exclude amounts that were capitalized and subsequently expensed in the period. All of these costs have been capitalized for less than one year. 200920082007 (in millions) Balance at January 1,$17.0 $ 1.5 $ 10.5 Additions to capitalized exploratory well costs pending the determination of proved reserves51.7 17.0 1.5 Reclassifications to property, plant and equipment after the determination of proved reserves(14.3)Capitalized exploratory well costs charged to expense(2.7)(1.5)(10.5) Balance at December 31, $51.7 $17.0 $ 1.5

Note 6 - Fair-Value Measures

Note 6 - Fair-Value Measures
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Fair-Value Measures	Note 6 - Fair Value Measurements Beginning in 2008, Questar adopted the effective provisions of ASC 820 "Fair Value Measurements and Disclosures." ASC 820 defines fair value in applying GAAP, establishes a framework for measuring fair value and expands disclosures about fair-value measurements. ASC 820 does not change existing guidance as to whether or not an instrument is carried at fair value. ASC 820 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. The Level 2 fair value of derivative contracts (see Note 7) is based on market prices posted on the NYMEX on the last trading day of the reporting period and industry-standard discounted cash flow models. The Level 3 fair value of derivative contracts is based on NYMEX market prices in combination with unobservable volatility inputs and industry-standard option pricing models. Long-term investments consist of money market and short-term bond index mutual funds, and represent funds held in Wexpro's trust (see Note 4). The fair value of long-term investments is based on quoted prices for the underlying mutual funds, and is considered a Level 1 fair value. Questar primarily applies the market approach for recurring fair value measurements and maximizes its use of observable inputs and minimizes its use of unobservable inputs. Questar 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, Questar makes assumptions in valuing its assets and liabilities, including assumptions about risk and the risks inherent in the inputs to the valuation technique. Certain of Questar's derivative instruments, however, 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, 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 Questar. Derivative contract fair values are reported on a net basis to the extent a legal right of offset with a counterparty exists. In February 2008, the FASB delayed the effective date of ASC 820 for one year for certain nonfinancial assets and nonfinancial liabilities, except those recognized or disclosed at fair value in the financial statements on a recurring basis. On January 1, 2009, Questar adopted, without material impact on the Consolidated Financial Statements, the delayed provisions of ASC 820

Note 7 - Derivative Contracts

Note 7 - Derivative Contracts
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Derivative Contracts	Note 7 - Derivative Contracts Market Resources' subsidiaries use commodity-price derivative instruments in the normal course of business. Market Resources has established policies and procedures for managing commodity-price risks through the use of derivative instruments. On January 1, 2009, the Company adopted a revision to ASC 815 "Derivatives and Hedging", which requires more detailed information about hedging transactions including the location and effect on the primary consolidated financial statements. Market Resources uses derivative instruments to support rate of return and cash flow targets and protect earnings from downward movements in commodity prices. However, these same instruments typically limit future gains from favorable price movements. Derivative contracts are currently in place for a significant share of Questar E&P-owned gas and oil production and a portion of Energy Trading gas marketing transactions. The volume of production with associated derivative instruments and the mix of the instruments are frequently evaluated and adjusted by management in response to changing market conditions. Market Resources may match derivative contracts with up to 100% of forecast production from proved reserves when prices meet earnings and cash flow objectives. Market Resources does not enter into derivative instruments for speculative purposes. Market Resources uses derivative instruments known as fixed-price swaps and costless collars to realize a known price or range of prices for a specific volume of production delivered into a regional sales point. Swap agreements do not require the physical transfer of natural gas between the parties at settlement. Swap transactions are settled in cash with one party paying the other for the net difference in prices, multiplied by the relevant volume, for the settlement period. Collars are combinations of put and call options that have a floor price and a ceiling price and are only triggered if the settlement price is outside the range of the floor and ceiling prices. In the past, Questar E&P has also used natural gas basis-only swaps to protect cash flows and net income from widening natural gas-price basis differentials. However, natural gas basis-only swaps exposed the Company to losses from narrowing natural gas price-basis differentials. Market Resources enters into derivative instruments that do not have margin requirements or collateral provisions that would require funding prior to the scheduled cash settlement dates. Derivative-arrangement counterparties are normally financial institutions and energy-trading firms with investment-grade credit ratings. The Company routinely monitors and manages its exposure to counterparty risk by requiring specific minimum credit standards for all counterparties and transacting with multiple counterparties. All derivative instruments are required to be recorded on the balance sheet as either assets or a liabilities measured at their fair values. The designation of a derivative instrument as a hedge and its ability to meet hedge accounting criteria determines how the change in fair value of the derivative instrument is reflected in the consolidated financi

Note 8 - Debt

Note 8 - Debt
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Debt	Note 8 - Debt The Company has short-term line-of-credit commitments from several banks under which it may borrow up to $435.0 million at December 31, 2009. These credit lines have interest-rate options generally below the prime interest rate. Commercial-paper borrowings with initial maturities of less than one year are backed by these short-term line-of-credit arrangements. These credit arrangements carry annual facility or commitment fees on the unused balance. The details of short-term debt are as follows: December 31, 20092008 (in millions) Commercial paper with variable-interest rates$169.0 $151.1 Weighted-average interest rate0.31%4.59%Short-term bank debt with variable-interest rates$ 80.0 Weighted-average interest rate2.34% All short-term and long-term notes and the term-bank loan are unsecured obligations and rank equally with all other unsecured liabilities. Market Resources' $800.0 million revolving-credit facility had $200.0 million outstanding at a weighted-average interest rate of 0.73% at December 31, 2009. This credit agreement carries an annual commitment fee of 0.115% on the unused balance. At December 31, 2009, Market Resources could pay dividends of $1.1 billion without violating the terms of its debt covenants. The terms of the Questar Pipeline and Questar Gas debt obligations do not have dividend-payment restrictions. In August 2009, Market Resources issued $300.0 million of notes due March 2020 with a 6.82% effective interest rate and used the net proceeds to reduce the balance outstanding under its long-term revolving-credit facility. In September 2009, Questar Pipeline issued $50.0 million of notes due February 2018 with a 5.40% effective interest rate and used the net proceeds to repay $42.0 million of long-term notes that matured in October 2009. The details of long-term debt are as follows: December 31, 20092008 (in millions) Market ResourcesRevolving-credit facility, 0.73% at December 31, 2009, due 2013$ 200.0 $ 450.0 7.50% notes due 2011150.0 150.0 6.05% notes due 2016250.0 250.0 6.80% notes due 2018450.0 450.0 6.80% notes due 2020300.0 Questar PipelineMedium-term notes 6.45% to 7.55%, due 2011 to 2018210.2 252.2 5.83% notes due 2018250.0 200.0 Questar Gas Medium-term notes 5.02% to 6.91%, due 2011 to 2018220.0 220.0 6.30% notes due 201850.0 50.0 7.20% notes due 2038100.0 100.0 Total Long-Term Debt Outstanding2,180.2 2,122.2 Less current portion(42.0)Less unamortized-debt discount(1.6)(1.3)Plus unamortized-debt premium1.3 Total Long-Term Debt$2,179.9 $2,078.9 Maturities of long-term debt for the five years following December 31, 2009, are $332.0 million in 2011, $91.5 million in 2012 and $242.0 million in 2013.

Note 9 - Income Taxes

Note 9 - Income Taxes
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Income Taxes	Note 9 - Income Taxes Details of Questar's income tax expense and deferred income taxes are provided in the following tables. The components of income tax expense were as follows: Year Ended December 31, 200920082007 (in millions) Federal Current$ 31.2 $ 4.5 $ 93.7 Deferred178.8 362.3 173.8 State Current5.2 (3.6)5.9 Deferred7.2 15.2 17.6 Deferred investment tax credits recognized(0.4)(0.4)(0.4) $222.0 $378.0 $290.6 The difference between the statutory federal income tax rate and the Company's effective income tax rate is explained as follows: Year Ended December 31,200920082007Federal income taxes statutory rate35.0%35.0%35.0%Increase (decrease) in rate as a result of:State income taxes, net of federal income tax benefit1.3 0.7 1.9 Domestic production benefit(0.2)Amortize investment-tax credits related to rate-regulated assets(0.1)(0.1)Tax benefits from dividends paid to ESOP(0.2)(0.1)(0.1)Other(0.1)(0.1) Effective income tax rate 35.9%35.6%36.4% Significant components of the Company's deferred income taxes were as follows: December 31, 20092008 (in millions) Deferred tax liabilitiesProperty, plant and equipment$1,674.2 $1,422.8 Energy-price derivatives 13.6 Total deferred tax liabilities1,674.2 1,436.4 Deferred tax assetsEnergy-price derivatives 29.5 Employee benefits and compensation costs91.2 102.3 Total deferred tax assets120.7 102.3 Deferred income taxes - noncurrent$1,553.5 $1,334.1 Deferred income taxes - currentEnergy-price derivatives$8.0 ($160.4) Other27.529.8 Deferred income taxes - current asset (liability)$ 35.5 ($130.6)

Note 10 - Commitments and Conti

Note 10 - Commitments and Contingencies
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Commitments and Contingencies	Note 10 - Commitments and Contingencies Questar is involved in various commercial and regulatory claims and litigation and other legal proceedings that arise in the ordinary course of its business. Management does not believe any of them will have a material adverse effect on the Company's financial position, results of operations or cash flows. A liability is recorded for a loss contingency when its occurrence is probable and damages can be reasonably estimated based on the anticipated most likely outcome. Disclosures are provided for contingencies reasonably likely to occur which would have a material adverse effect on the Company's financial position, results of operations or cash flows. Some of the claims involve highly complex issues relating to liability, damages and other matters subject to substantial uncertainties and, therefore, the probability of liability or an estimate of loss cannot be reasonably determined. Environmental Claims In United States of America v. Questar Gas Management Co., Civil No. 208CV167, filed on February 29, 2008, in Utah Federal District Court, the Environmental Protection Agency (EPA) alleges that Gas Management violated the federal Clean Air Act (CAA) and seeks substantial penalties and a permanent injunction involving the manner of operation of five compressor stations located in the Uinta Basin of eastern Utah. EPA further alleges that the facilities are located within the original boundaries of the former Uncompahgre Indian Reservation and are therefore within "Indian Country." EPA asserts primary CAA jurisdiction over "Indian Country" where state CAA programs do not apply. EPA contends that the potential to emit, on a hypothetically uncontrolled basis, for Gas Management's facilities render them "major sources" of emissions for criteria and hazardous air pollutants. Categorization of the facilities as "major sources" affects the particular regulatory program applicable to those facilities. EPA claims that Gas Management failed to obtain the necessary major source pre-construction or modification permits, and failed to comply with hazardous air-pollutant regulations for testing and reporting, among other things. Gas Management contends that its facilities have pollution controls installed that reduce their actual air emissions below major source thresholds, rendering them subject to different regulatory requirements. Gas Management intends to vigorously defend against the EPA's claims, and believes that the major source permitting and regulatory requirements at issue can be legally avoided by applying Utah's CAA program or EPA's prior practice for similar facilities elsewhere in Indian Country, among other defenses. Because of the complexities and uncertainties of this legal dispute, it is difficult to predict all reasonably possible outcomes; however, management believes the Company has accrued a reasonable loss contingency that is an immaterial amount, for the anticipated most likely outcome. On July 10, 2009, Questar E&P filed a petition with the U.S. Tenth Circuit Court of Appeals challenging an administrative compliance order dated May 12, 2009, (Order) issued by the EPA which asserts that Questar

Note 11 - Wexpro Agreement

Note 11 - Wexpro Agreement
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Wexpro Agreement	Note 11 - Wexpro Agreement Wexpro's operations are subject to the terms of the Wexpro Agreement. The agreement was effective August 1, 1981, and sets forth the rights of Questar Gas utility operations to receive certain benefits from Wexpro's operations. The agreement was approved by the PSCU and PSCW in 1981 and affirmed by the Supreme Court of Utah in 1983. Major provisions of the agreement are as follows. a. Wexpro conducts gas-development drilling on a finite group of productive gas properties, as defined in the agreement, and bears any costs of dry holes. Natural gas produced from successful drilling on these properties is delivered to Questar Gas. Wexpro is reimbursed for the costs of producing the natural gas plus a return on its investment in successful wells. The after-tax return allowed Wexpro is adjusted annually and is approximately 20.5%. b. Wexpro operates certain natural gas properties for Questar Gas. Wexpro is reimbursed for its costs of operating these properties, including a rate of return on any investment it makes. This after-tax rate of return is adjusted annually and is approximately 12.5%. c. Crude-oil production from certain oil-producing properties is sold at market prices with the revenues used to recover operating expenses and to provide Wexpro a return on its investment. The after-tax rate of return on investments in these properties is adjusted annually and is approximately 12.5%. Any operating income remaining after recovery of expenses and Wexpro's return on investment is divided between Wexpro and Questar Gas, with Wexpro retaining 46%. d. Wexpro conducts developmental-oil drilling on productive oil properties and bears any costs of dry holes. Oil discovered from these properties is sold at market prices with the revenues used to recover operating expenses and to give Wexpro a return on its investment in successful wells. The after-tax rate of return is adjusted annually and is approximately 17.5%. Any operating income remaining after recovery of expenses and Wexpro's return on investment is divided between Wexpro and Questar Gas with Wexpro retaining 46%. Questar Gas received oil-income sharing of $1.0 million in 2009, $6.1 million in 2008 and $4.9 million in 2007. e. Amounts received by Questar Gas from the sharing of Wexpro's oil income are used to reduce natural-gas costs to utility customers. Wexpro's net investment base and the yearly average rate of return for 2009 and the previous two years are shown in the table below: 200920082007Wexpro's net investment base (in millions)$431.9 $410.6 $300.4 Average annual rate of return (after tax)19.9%19.9%19.9%

Note 12 - Rate Regulation

Note 12 - Rate Regulation
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Rate Regulation	Note 12 - Rate Regulation Questar Gas Rate Changes Questar Gas filed a general rate case in Utah in December 2009, requesting an allowed return on equity of 10.6%, an increase in rates of $17.2 million, a mechanism to adjust rates for investment in feeder line replacement, and a continuation of the CET. Questar Gas filed a general rate case in Utah in December 2007. The PSCU allowed Questar Gas to increase its non-gas distribution revenues by an annualized $12.0 million beginning August 15, 2008 and authorized a 10.0% return on equity. Questar Gas filed a general rate case in Wyoming in August 2008. The PSCW authorized a 10.5% return on equity. In January 2007 the PSCU approved a demand-side management program (DSM) effective January 1, 2007. Under the DSM, Questar Gas encourages the conservation of natural gas through advertising, rebates for efficient homes and appliances, and energy audits. The costs related to the DSM are deferred and recovered from customers through periodic rate adjustments. Questar Gas received revenues for recovery of DSM costs amounting to $26.9 million in 2009 compared with $6.6 million in 2008. As of December 31, 2009, Questar Gas had a regulatory asset of $40.6 million for DSM costs to be recovered from customers. In October 2006, the PSCU approved a three-year pilot program for a conservation enabling tariff (CET) effective January 1, 2006, to promote energy conservation. Under the company's prior rate structure, non-gas revenues declined when average temperature-adjusted usage per customer declined while non-gas revenues increased when average temperature-adjusted usage per customer increased. Under the CET, Questar Gas non-gas revenues are decoupled from the temperature-adjusted usage per customer. The tariff specifies a margin per customer for each month with differences to be deferred and recovered from customers or refunded to customers through periodic rate adjustments. These adjustments are limited to five percent of distribution non-gas revenues. Under the CET, Questar Gas recorded a $4.0 million revenue decrease in 2009 compared with a $1.0 million increase in 2008. In late 2007, the PSCU ordered a continuation of the CET program for an additional two years. Other Regulatory Assets and Liabilities The Company has other regulatory assets and liabilities in addition to purchased-gas adjustments. The rate-regulated entities recover the costs of assets but do not generally receive a return on these assets. Following is a description of the Company's regulatory assets: - Gains and losses on the reacquisition of debt by rate-regulated companies are deferred and amortized as interest expense over the would-be remaining life of the reacquired debt. The reacquired debt costs had a weighted-average life of approximately 10.0 years as of December 31, 2009. - The CET asset (liability) represents actual revenues received that are less than (in excess of) the allowed revenues. These amounts are recovered (refunded) through periodic rate adjustments. - The DSM program liability represents funds available for the program that exceed amounts expended to date. These amounts are refunded through periodic rate adjustments.-

Note 13 - Share-Based Compensat

Note 13 - Share-Based Compensation
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Share-Based Compensation	Note 13 - Share-Based Compensation Questar issues stock options and restricted shares to certain officers, employees and non-employee directors under its LTSIP and recognizes expense over time as the stock options or restricted shares vest. Share-based compensation expense amounted to $22.7 million in 2009 compared to $16.7 million in 2008 and $12.9 million in 2007. Deferred share-based compensation, representing the nonvested value of restricted share awards, amounted to $13.7 million at December 31, 2009 and $17.7 million at December 31, 2008. Deferred share-based compensation is included in common stock on the Consolidated Balance Sheets. Cash flow from income tax benefits in excess of recognized compensation expense amounted to $3.6 million in 2009, $13.2 million in 2008 and $11.1 million in 2007. There were 8,253,083 shares available for future grant at December 31, 2009. The Company uses the Black-Scholes-Merton mathematical model in estimating the fair value of stock options for accounting purposes. 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 was intended for measuring the value of options traded on an exchange. The calculated fair value of options granted and major assumptions used in the model at the date of grant are listed below: 200920082007 Range of Stock Option VariablesRange of StockOption VariablesInput VariablesFair value of options at grant date $31.06 - $35.38$28.58 - $53.83$41.08 Risk-free interest rate 1.78% - 2.51%2.72% - 3.20%4.77%Expected price volatility 28.1% - 29.9%20.3% - 32.3%22.4% Expected dividend yield 1.39% - 1.61%0.91 - 1.72%1.14%Expected life in years5.0 - 5.05.0 - 5.05.2 Unvested stock options increased by 819,827 shares to 1,677,327 in 2009. Stock-option transactions under the terms of the LTSIP for the three years ended December 31, 2009, are summarized below: OptionsOutstanding Price RangeWeighted Average Price Balance at January 1, 20075,372,708 $7.50 - $38.57 $14.32 Granted140,000 41.08 41.08 Exercised(883,107)7.50 - 17.55 12.78 Forfeited(1,000)14.01 14.01 Balance at December 31, 20074,628,601 7.50 - 41.08 15.42 Granted317,500 28.58 - 53.83 30.97 Exercised(763,026)7.50 - 17.55 10.33 Balance at December 31, 20084,183,075 7.50 - 53.83 17.53 Granted1,004,000 31.06 - 35.38 35.01 Exercised(471,582)7.50 - 14.01 9.19 Forfeited(60,000)28.58 - 35.38 29.15 Balance at December 31, 20094,655,493 $7.50 - $53.83 $21.99 Options OutstandingOptions ExercisableUnvested Options Range of exercisepricesNumber outstanding at Dec. 31, 2009Weighted-average remaining term in yearsWeighted-average exercise priceNumber exercisable at Dec. 31, 2009Weighted-average exercise priceNumber unvested at Dec. 31, 2009Weighted-average exercise price $ 7.50 72,4260.1$7.5072,426$7.50 11.48 - 11.98 855,4882.111.58855,48811.58 13.56 - 14.86 1,811,8052.413.711,811,80513.7117.55 - 31.06 396,7745.727.42191,77925.54204,995$29.18 $33.86 - $53.83 1,519,0005.237.0146,66841.081,472,33236.884,655,4933.5$21.992,978,166$14.141,677,327$35.94 Restricted shares are valued at the grant-date market price and amortized to expense over th

Note 14 - Employee Benefits

Note 14 - Employee Benefits
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Employee Benefits	Note 14 - Employee Benefits Defined Benefit Pension Plan and Other Postretirement Benefits The Company has defined-benefit pension and life insurance plans covering a majority of its employees and a postretirement medical plan providing coverage to less than half of its employees. The Company's Employee Benefits Committee (EBC) has oversight over investment of retirement-plan and postretirement-benefit assets. The EBC uses a third-party consultant to assist in setting targeted-policy ranges for the allocation of assets among various investment categories. The majority of retirement-benefit assets were invested as follows: Actual AllocationPolicy Range Year Ended December 31, 2009200820092008Total domestic equity securities41%37%35-45%35-45%Foreign equity securities Developed market foreign equity securities19%15% Emerging market foreign equity securities7%5%Total foreign securities26%20%25-35%20-30%Debt securities Investment grade intermediate term debt14%35% Investment grade long-term debt11% Below-investment grade debt7%3%Total debt securities32%38%25-35%26-34%Real estate securities4%n/a3-7%Cash and short-term investments1%1%0-3%0-3% At the end of 2009 domestic equity assets were invested in a passive total stock market index fund that invests in a diversified portfolio of stocks representative of the whole U.S. stock market. Developed market foreign equity assets were invested in funds that hold a diversified portfolio of common stocks of corporations in developed countries outside the United States. These investments are benchmarked against the Morgan Stanley Capital International Europe Australasia and Far East (or MSCI EAFE) index. Emerging market foreign equity assets are invested in funds that hold a diversified portfolio of common stocks of corporations in emerging countries outside the United States. This investment is benchmarked against the MSCI EAFE Emerging Markets index. Investment grade intermediate-term debt assets are invested in funds holding a diversified portfolio of debt of governments, corporations and mortgage borrowers with average maturities of 5 to 10 years and investment grade credit ratings. The investments are benchmarked against the Barclay's Aggregate Bond index. Investment grade long-term debt assets are invested in a diversified portfolio of debt of governments, corporations and mortgage borrowers with an average maturity of more than 10 years and investment grade credit ratings. These assets are benchmarked against the Barclay's Government/Credit Bond index. Below-investment grade debt assets are invested in a fund holding a diversified portfolio of debt securities of corporations with an average maturity up to 10 years with below-investment grade credit ratings. This investment is benchmarked against the Merrill Lynch High Yield II Total Return Bond index. Cash and short-term investments are held in a fund that purchases investment grade quality short term debt issued by governments and corporations. Questar funds a trust for Employee Retirement Income Security Act (ERISA) qualified retirement-benefit obligations to pay benefits currently due and to build asset balances over a reasonable time period to pay

Note 15 - Operations by Line of

Note 15 - Operations by Line of Business
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Operations by Line of Business	Note 15 - Operations by Line of Business Questar's major lines of business include gas and oil exploration and production (Questar E&P and Wexpro), midstream field services (Gas Management), energy marketing (Energy Trading), interstate gas transportation (Questar Pipeline), and retail gas distribution (Questar Gas). Line of business information is presented according to senior management's basis for evaluating performance including differences in the nature of products, services and regulation. Following is a summary of operations by line of business for the three years ended December 31, 2009: QuestarInterco.QuestarGasEnergyQuestarQuestar Consol.Trans.E&PWexproMgmt..TradingPipelineGasCorp.(in millions)2009RevenuesFrom unaffiliated customers$3,038.0 $1,267.3 $17.8 $238.3 $425.6 $170.1 $918.9 From affiliated companies($712.7)225.1 26.3 385.0 75.3 1.0 Total revenues3,038.0 (712.7)1,267.3 242.9 264.6 810.6 245.4 919.9 Operating expensesCost of natural gas and other products sold716.2 (702.6)790.6 1.6 626.6 Operating and maintenance369.2 (2.2)127.5 21.2 75.0 1.2 40.1 106.4 General and administrative183.8 (6.9)68.0 17.0 25.0 3.9 36.1 42.9 ($2.2)Production and other taxes105.3 58.3 20.0 4.6 8.6 13.3 0.5 Depreciation, depletion and amortization706.2 512.8 58.8 44.3 2.0 44.3 43.8 0.2 Other operating expenses45.3 (1.0)45.3 1.0 Total operating expenses2,126.0 (712.7)811.9 118.0 148.9 797.7 130.7 833.0 (1.5)Net gain (loss) from asset sales1.7 1.6 (0.3)(0.1)0.5 Operating income 913.7 457.0 124.6 115.6 12.9 115.2 86.9 1.5 Interest and other income (expense) (173.6)(72.6)(185.7)3.2 (0.2)71.5 2.5 7.6 0.1 Income from unconsol. affiliates6.5 0.1 2.6 3.8 Interest expense(128.7)72.6 (63.9)(0.9)(6.0)(70.9)(29.5)(28.5)(1.6)Income tax expense(222.0)(72.6)(46.2)(40.0)(5.0)(33.8)(24.4) Net income 395.9 134.9 80.7 72.0 8.5 58.2 41.6 Net income attributable to non- controlling interest(2.6)(2.6) Net income attributable to Questar$393.3 $134.9 $80.7 $69.4 $8.5 $58.2 $41.6 Identifiable assets$8,862.2 $4,614.0 $617.4 $924.3 $206.8 $1,162.5 $1,332.2 $5.0 Goodwill69.9 60.1 4.2 5.6 Investment in unconsol. affiliates72.0 43.9 28.1 Cash capital expenditures1,498.2 1,108.6 116.2 88.3 1.5 100.8 82.6 0.2 Accrued capital expenditures1,400.8 1,033.7 110.1 73.3 1.4 94.5 87.6 0.2 2008RevenuesFrom unaffiliated customers$3,465.1 $1,392.1 $31.1 $265.9 $608.1 $173.7 $ 994.2 From affiliated companies($1,149.7)209.9 24.3 834.5 74.9 6.1 Total revenues3,465.1 (1,149.7)1,392.1 241.0 290.2 1,442.6 248.6 1,000.3 Operating expensesCost of natural gas and other products sold1,007.6 (1,136.0)0.5 1,404.4 1.8 736.9 Operating and maintenance367.6 (1.7)125.4 23.5 95.0 1.2 37.1 87.1 General and administrative166.1 (5.9)55.8 13.7 23.7 3.0 36.8 38.7 $0.3 Production and other taxes164.9 104.0 37.7 2.6 0.3 7.8 11.9 0.6 Depreciation, depletion and amortization494.4 330.9 48.5 28.7 1.9 42.7 41.5 0.2 Other operating expenses88.7 (6.1)73.9 6.1 0.8 14.0 Total operating expenses2,289.3 (1,149.7)690.5 129.5 150.8 1,410.8 140.2 916.1 1.1 Net gain (loss) from asset sales64.7 60.4 (0.2)4.5 Operating income (loss) 1,240.5 762.0 111.3 139.4 31.8 112.9 84.2 (1.1)Interest and other income (expense) (52.5)(78.4)(71.7)6

Note 16 - Quarterly Financial I

Note 16 - Quarterly Financial Information (Unaudited)
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Quarterly Financial Information (Unaudited)	Note 16 - Quarterly Financial Information (Unaudited) A reclassification of first, second and third quarter 2009 revenues and realized loss on basis-only swaps increased both line items by $3.4 million, $4.6 million and $7.2 million, respectively. Following is a summary of unaudited quarterly financial information: FirstSecondThirdFourthQuarterQuarterQuarterQuarterYear(in millions, except per-share amounts)2009Revenues $922.5$617.7$607.0$890.8$3,038.0 Operating income270.5180.1198.8264.3913.7 Net income67.778.598.8150.9395.9Net income attributable to Questar67.277.998.2150.0393.3 Basic earnings per common share0.390.440.570.862.26 Diluted earnings per common share0.380.440.560.852.23 2008Revenues $1,000.5 $825.8 $760.0 $878.8 $3,465.1 Operating income308.6 284.6 375.5 271.8 1,240.5 Net income188.2174.7206.6123.3692.8Net income attributable to Questar185.8 172.6 204.2 121.2 683.8 Basic earnings per common share1.08 1.00 1.18 0.70 3.96 Diluted earnings per common share1.05 0.98 1.16 0.69 3.88

Note 17 - Supplemental Gas and

Note 17 - Supplemental Gas and Oil Information (Unaudited)
	12 Months Ended Dec. 31, 2009 USD / shares
Notes To Financial Statements [Abstract]
Supplemental Gas and Oil Information (Unaudited)	Note 17 - Supplemental Gas and Oil Information (Unaudited) The Company is making the following supplemental disclosures of gas and oil producing activities, in accordance with ASC 932 "Extractive Activities - Oil and Gas" as amended by ASU 2010-03 "Oil and Gas Reserve Estimation and Disclosures" and SEC Regulation S-X. The Company uses the successful efforts accounting method for its gas and oil exploration and development activities and for cost-of-service gas and oil properties. Questar E&P Activities The following information is provided with respect to Questar E&P's gas and oil exploration and production activities, which are all located in the United States. Capitalized Costs The aggregate amounts of costs capitalized for gas and oil exploration and development activities and the related amounts of accumulated depreciation, depletion and amortization are shown below: December 31, 20092008 (in millions) Proved properties$5,721.5 $ 4,948.2 Unproved properties389.6 193.2 6,111.1 5,141.4 Accumulated depreciation, depletion and amortization(1,890.9)(1,421.8)Net capitalized costs$4,220.2 $ 3,719.6 Costs Incurred The costs incurred in gas and oil exploration and development activities are displayed in the table below. The costs incurred to develop proved undeveloped reserves were $216.1 million in 2009, $219.9 million in 2008 and $125.8 million in 2007. Year Ended December 31, 200920082007 (in millions) Property acquisition Unproved$ 215.1 $ 167.3 $ 28.9 Proved6.4 602.7 45.1 Exploration (capitalized and expensed)92.9 58.7 14.9 Development741.1 1,061.2 652.2 Total costs incurred$1,055.5 $1,889.9 $741.1 Results of Operation Following are the results of operation of Questar E&P gas and oil exploration and development activities, before corporate overhead and interest expenses. Year Ended December 31, 200920082007 (in millions) Revenues$1,267.3 $1,392.1 $956.0 Production costs185.8 229.4 148.0 Exploration expenses25.0 29.3 22.0 Depreciation, depletion and amortization512.8 330.9 243.5 Abandonment and impairment20.3 44.6 10.8 Total expenses743.9 634.2 424.3 Revenues less expenses523.4 757.9 531.7 Income taxes (183.2)(269.1)(197.3)Results of operation from producing activities excluding corporate overhead and interest expenses$ 340.2 $ 488.8 $334.4 Estimated Quantities of Proved Gas and Oil Reserves Estimates of proved gas and oil reserves have been completed in accordance with professional engineering standards and the Company's established internal controls, which includes the compliance oversight of a multi-functional reserves review committee responsible to the Company's board of directors. Questar E&P's estimated proved reserves have been prepared by Ryder Scott Company, L.P., independent reservoir engineering consultants, in accordance with the SEC's Regulation S-X and ASC 932 as amended. The individuals performing reserves estimates possess professional qualifications and demonstrate competency in reserves estimation and evaluation. Natural Gas Natural GasOil and NGLEquivalents (Bcf)(MMbbl)(Bcfe)Proved ReservesBalance at January 1, 20071,461.2 28.4 1,631.4 Revisions - Previous estimates26.3 3.3 46.2 Pinedale increased-density(a) 120.6 1.0 126.

Schedule of Valuation and Quali

Schedule of Valuation and Qualifying Accounts
	12 Months Ended Dec. 31, 2009 USD / shares
Schedule to Financial Statements [Abstract]
Schedule of Valuation and Qualifying Accounts	Financial Statement Schedule: QUESTAR CORPORATION Schedule of Valuation and Qualifying AccountsColumn DColumn CDeductions forColumn ADescriptionColumn BBeginning BalanceAmounts chargedto expenseaccounts written off and otherColumn EEnding Balance(in millions)Year Ended December 31, 2009Allowance for bad debts$8.5$3.8($3.9)$8.4Year Ended December 31, 2008Allowance for bad debts6.0 7.0 (4.5)8.5 Allowance for notes receivable2.8 (2.8)Year Ended December 31, 2007Allowance for bad debts7.8 2.6 (4.4)6.0 Allowance for notes receivable3.1 (0.3)2.8

Document Information

Document Information
	12 Months Ended Dec. 31, 2009 USD / shares
Document Information [Text Block]
Document Type	10-K
Document Period End Date	2009-12-31
Amendment Flag	false

Entity Information

Entity Information (USD $)
	12 Months Ended Dec. 31, 2009	Jun. 30, 2009
Entity [Text Block]
Entity Registrant Name	Questar Corporation
Entity Central Index Key	0000751652
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Well Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Public Float		$5,400,000,000
Entity Common Stock Shares Outstanding	174,644,902