Condensed Consolidated Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Operating Revenues:
Natural gas sales	$ 15,828	$ 36,368	$ 36,691	$ 89,649
Natural gas transportation	251,691	248,322	761,659	726,767
Natural gas storage	34,714	35,392	105,171	107,255
Other	724	1,612	3,079	4,230
Total operating revenues	302,957	321,694	906,600	927,901
Operating Costs and Expenses:
Cost of natural gas sales	15,828	36,368	36,691	89,649
Cost of natural gas transportation	8,104	9,349	27,264	27,695
Operation and maintenance	78,480	68,988	214,068	201,465
Administrative and general	42,443	34,900	131,225	113,527
Depreciation and amortization	66,693	66,300	199,068	196,556
Taxes - other than income taxes	12,644	11,930	39,110	37,328
Other (income) expense, net	7,753	4,600	31,214	(1,500)
Total operating costs and expenses	231,945	232,435	678,640	664,720
Operating Income	71,012	89,259	227,960	263,181
Other (Income) and Other Deductions:
Interest expense	21,132	23,887	68,518	71,582
Interest income - affiliates	(9)	(6)	(24)	(22)
Allowance for equity and borrowed funds used during construction (AFUDC)	(5,886)	(3,118)	(14,468)	(12,513)
Equity in earnings of unconsolidated affiliates	(2,127)	(1,355)	(5,395)	(3,768)
Miscellaneous other (income) deductions, net	(2,060)	777	(4,097)	1,678
Total other (income) and other deductions	11,050	20,185	44,534	56,957
Net Income	59,962	69,074	183,426	206,224
Equity interest in unrealized gain (loss) on interest rate hedge	(283)	(316)	(441)	(556)
Comprehensive Income	$ 59,679	$ 68,758	$ 182,985	$ 205,668