Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net income	$ 57.2	$ 64.3	$ 55.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	61.0	60.6	58.8
Deferred income taxes	35.7	52.9	46.0
Other adjustments for non-cash items	3.2	1.4	1.5
Changes in operating assets and liabilities	44.0	(63.1)	(47.8)
Net cash provided by operating activities	201.1	116.1	113.7
Investing Activities
Property, plant and equipment purchased	(240.4)	(217.4)	(174.7)
Property, plant and equipment purchased from affiliates	(10.8)	(0.1)	0.0
Acquisition of gas distribution system	0.0	(11.4)	0.0
Cash used in disposition of assets	0.0	(3.9)	(3.4)
Proceeds from disposition of assets	0.5	0.4	0.8
Net cash used in investing activities	(250.7)	(232.4)	(177.3)
Financing Activities
Issuance of short-term debt, net	200.0	0.0	0.0
Issuance of long-term debt	100.0	0.0	0.0
Issuance (repayment) of affiliated current borrowings, net	(225.3)	154.0	101.6
Other financing	(0.7)	0.0	0.0
Net cash provided by financing activities	46.7	107.0	74.6
Increase (decrease) in cash and cash equivalents	(2.9)	(9.3)	11.0
Cash and cash equivalents at beginning of year	10.5	19.8	8.8
Cash and cash equivalents at end of year	7.6	10.5	19.8
Supplemental Cash Flow Information
Interest and related charges, excluding capitalized amounts	29.3	27.6	26.3
Income taxes	(35.0)	21.1	13.2
Significant noncash investing activities:
Accrued capital expenditures	19.7	22.2	17.2
Dominion Questar
Financing Activities
Equity contribution from Dominion Questar	2.7	0.0	0.0
Dividends paid to Dominion Questar	$ (30.0)	$ (47.0)	$ (27.0)