Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2011

Notes to Financial Statements [Abstract]

Property, Plant and Equipment Summary [Table Text Block]

			December 31,
		Lives in Years (1)	2011 (2)		2010 (2)
				(In thousands)
Regulated Operations:
	Distribution plant	9-60	$	1,042,857	$	1,001,032
	Gathering and processing plant	26		166,990		183,548
	Transmission plant	5-46		2,321,009		2,239,762
	General - LNG	5-40		1,118,791		1,117,418
	Underground storage plant	5-46		321,920		314,744
	General plant and other	3-50		304,385		283,737
	Construction work in progress			48,268		52,800
				5,324,220		5,193,041
Less accumulated depreciation and amortization				1,219,017		1,074,161
				4,105,203		4,118,880
Non-regulated Operations:
	Distribution plant	5-40		60,466		59,749
	Gathering and processing plant	1-50		1,839,571		1,740,725
	General plant and other	3-29		19,758		17,274
	Construction work in progress			55,594		67,464
				1,975,389		1,885,212
Less accumulated depreciation and amortization				354,256		299,633
				1,621,133		1,585,579
Net property, plant and equipment			$	5,726,336	$	5,704,459

Computer software cost [Table Text Block]

Unamortized computer software cost	$	140,397	$	131,182
Less accumulated amortization		89,258		79,637
Net capitalized computer software costs	$	51,139	$	51,545