Segment Information (Tables)

9 Months Ended

Sep. 30, 2014

Segment Information [Abstract]

Company's Segment Information, Continuing Operations

	Three Months Ended						Three Months Ended
	September 30, 2014						September 30, 2013
	Regulated		Other		Consolidated		Regulated		Other		Consolidated
Operating revenues	$	203,303	$	7,232	$	210,535	$	197,857	$	4,463	$	202,320
Operations and maintenance expense		68,319		4,055		72,374		67,737		3,894		71,631
Depreciation		29,273		209		29,482		29,873		107		29,980
Operating income (loss)		92,783		2,275		95,058		86,232		(92)		86,140
Interest expense, net of AFUDC		16,805		990		17,795		17,314		1,610		18,924
Income tax expense (benefit)		8,832		59		8,891		5,435		(752)		4,683
Income (loss) from continuing operations		67,221		490		67,711		63,566		(817)		62,749
	Nine Months Ended						Nine Months Ended
	September 30, 2014						September 30, 2013
	Regulated		Other		Consolidated		Regulated		Other		Consolidated
Operating revenues	$	571,180	$	17,334	$	588,514	$	562,035	$	12,780	$	574,815
Operations and maintenance expense		204,291		10,144		214,435		200,641		9,196		209,837
Depreciation		91,378		311		91,689		88,565		(229)		88,336
Operating income		236,638		5,124		241,762		231,032		1,796		232,828
Interest expense, net of AFUDC		50,654		3,440		54,094		51,334		5,031		56,365
Income tax expense (benefit)		20,701		(769)		19,932		20,483		(2,248)		18,235
Income (loss) from continuing operations		165,587		(657)		164,930		159,380		(2,763)		156,617
Capital expenditures		219,465		1,274		220,739		214,575		832		215,407

Company's Segment Information, Assets

	September 30,		December 31,
	2014		2013
Total assets:
Regulated	$	5,146,961	$	4,893,573
Other		160,220		158,244
Consolidated	$	5,307,181	$	5,051,817