Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Schedule of Checks Outstanding but Not Yet Presented for Payment

The following table illustrates the checks outstanding but not yet presented for payment and recorded in accounts payable for the Companies:

Year Ended December 31,	2016	2015
(millions)
Dominion	$24	$27
Virginia Power	11	11
Dominion Gas	9	7

Schedule of Depreciation Rates

The Companies' average composite depreciation rates on utility property, plant and equipment are as follows:

Year Ended December 31,	2016	2015	2014
(percent)
Dominion
Generation	2.83	2.78	2.66
Transmission	2.47	2.42	2.38
Distribution	3.02	3.11	3.12
Storage	2.29	2.42	2.39
Gas gathering and processing	2.66	3.19	2.81
General and other	4.12	3.67	3.62
Virginia Power
Generation	2.83	2.78	2.66
Transmission	2.36	2.33	2.34
Distribution	3.32	3.33	3.34
General and other	3.49	3.40	3.29
Dominion Gas
Transmission	2.43	2.46	2.40
Distribution	2.55	2.45	2.47
Storage	2.19	2.44	2.40
Gas gathering and processing	2.58	3.20	2.82
General and other	4.54	4.72	5.77

Property, Plant and Equipment

Dominion's nonutility property, plant and equipment is depreciated using the straight-line method over the following estimated useful lives:

Asset	Estimated Useful Lives
Merchant generation-nuclear	44 years
Merchant generation-other	15-36 years
Nonutility gas gathering and processing	3-50 years
General and other	5-59 years

Major classes of property, plant and equipment and their respective balances for the Companies are as follows:

At December 31,	2016		2015
(millions)
Dominion
Utility:
Generation	$	17,147	$	15,656
Transmission	14,315		11,461
Distribution	16,381		13,128
Storage	2,814		2,460
Nuclear fuel	1,537		1,464
Gas gathering and processing	216		799
Oil and gas	1,652		—
General and other	1,450		927
Plant under construction	6,254		5,550
Total utility	61,766		51,445
Nonutility:
Merchant generation-nuclear	1,419		1,339
Merchant generation-other	4,149		2,683
Nuclear fuel	897		938
Gas gathering and processing	619		—
Other-including plant under construction	706		1,371
Total nonutility	7,790		6,331
Total property, plant and equipment	$	69,556	$	57,776
Virginia Power
Utility:
Generation	$	17,147	$	15,656
Transmission	7,871		6,963
Distribution	10,573		10,048
Nuclear fuel	1,537		1,464
General and other	745		709
Plant under construction	2,146		2,793
Total utility	40,019		37,633
Nonutility-other	11		6
Total property, plant and equipment	$	40,030	$	37,639
Dominion Gas
Utility:
Transmission	$	4,231	$	3,804
Distribution	3,019		2,765
Storage	1,627		1,583
Gas gathering and processing	198		797
General and other	184		165
Plant under construction	448		443
Total utility	9,707		9,557
Nonutility:
Gas gathering and processing	$	619	$	—
Other-including plant under construction	149		136
Total nonutility	768		136
Total property, plant and equipment	$	10,475	$	9,693