Condensed Consolidated Statement of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net income	$ 217,269	$ 187,024
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	137,153	130,738
Allowance for equity funds used during construction (equity AFUDC)	(5,469)	(7,350)
Changes in operating assets and liabilities:
Receivables - affiliates	1,808	(1,161)
Receivables - trade and other	37,509	(29,402)
Transportation and exchange gas receivable	2,506	(4,320)
Inventories	(26,632)	(15,574)
Payables - affiliates	15,596	7,088
Payables - trade	(103,555)	17,180
Accrued liabilities	(10,567)	2,783
Reserve for rate refunds	20,075	39,079
Asset retirement obligation removal costs	(7,555)	(9,092)
Other, net	(4,602)	49,278
Net cash provided by operating activities	273,536	366,271
Cash flows from financing activities:
Cash distributions to parent	(235,000)	(123,000)
Cash contributions from parent	94,000	107,000
Other, net	6,830	17,796
Net cash provided by (used in) financing activities	(134,170)	1,796
Cash flows from investing activities:
Property, plant and equipment additions, net of equity AFUDC	(219,971)	(278,832)
Contributions and advances for construction costs	23,801	20,680
Disposal of property, plant and equipment, net	2,958	426
Advances to affiliate, net	59,578	(101,805)
Return of capital from unconsolidated affiliates	469	398
Purchase of ARO Trust investments	(35,012)	(20,452)
Proceeds from sale of ARO Trust investments	27,411	14,844
Other, net	1,414	(3,400)
Net cash used in investing activities	(139,352)	(368,141)
Increase (decrease) in cash	14	(74)
Cash at beginning of period	113	185
Cash at end of period	127	111
Increase to property, plant and equipment	(253,298)	(326,798)
Changes in related accounts payable and accrued liabilities	33,327	47,966
Property, plant and equipment additions, net of equity AFUDC	$ (219,971)	$ (278,832)