Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$ 19us-gaap_NetIncomeLoss	$ 22us-gaap_NetIncomeLoss
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	28	26
Allowance for equity funds	0	(1)
Deferred income taxes and amortization of investment tax credits	11	12
Amortization of Deferred Charges	12us-gaap_AmortizationOfDeferredCharges	1us-gaap_AmortizationOfDeferredCharges
Deferred Energy Change	26sppc_DeferredEnergyChange	(22)sppc_DeferredEnergyChange
Amortization of other regulatory assets	(1)us-gaap_AmortizationOfRegulatoryAsset	12us-gaap_AmortizationOfRegulatoryAsset
Other, net	(8)us-gaap_OtherNoncashIncomeExpense	5us-gaap_OtherNoncashIncomeExpense
Changes in other operating assets and liabilities:
Accounts receivable and other assets	(11)	19
Inventories	0us-gaap_IncreaseDecreaseInInventories	(5)us-gaap_IncreaseDecreaseInInventories
Accounts payable and other liabilities	0	(1)
Net cash flows from operating activities	76	68
Cash flows from investing activities:
Capital expenditures	(48)	(55)
Proceeds from Contribution in Aid of Construction and Customer Advances	1	2
Payments for (Proceeds from) Other Investing Activities	2	0
Net cash flows from investing activities	(45)	(53)
Net change in cash and cash equivalents	31	15
Cash and cash equivalents at beginning of period	22	67
Cash and cash equivalents at end of period	$ 53	$ 82

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Other income (expense) included in net income that results in no cash inflows or outflows in the period. Includes noncash adjustments to reconcile net income (loss) to cash provided by (used in) operating activities that are not separately disclosed.

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The net cash outflow or inflow from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.

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