Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

For continuing operations, the statutory U.S. federal income tax rate reconciles to Questar Gas’ effective income tax rate as follows:

Three Months Ended March 31,	2018			2017
U.S. statutory rate		21.0	%		35.0	%
Increases (reductions) resulting from:
State taxes, net of federal benefit		3.7			3.1
Reversal of excess deferred income taxes		(1.2	)		—
Legislative change - state, net of federal benefits		(0.7	)		—
Other, net		0.1			—
Effective tax rate		22.9	%		38.1	%