Consolidated Statements of Operations and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Operating revenues	$ 759,159	$ 724,265	$ 1,441,105	$ 1,360,402
Operating expenses
Operation and maintenance	342,974	323,320	672,249	635,523
Depreciation and amortization	105,862	101,366	211,940	201,015
General taxes	56,894	57,806	117,661	117,952
(Gain) loss on asset dispositions and purchases	(345)	(114)	(615)	(208)
Total operating expenses, net	505,385	482,378	1,001,235	954,282
Operating income	253,774	241,887	439,870	406,120
Other income (expenses)
Interest, net	(73,668)	(77,757)	(147,228)	(155,871)
Allowance for funds used during construction			4,259	7,095
Amortization of debt expense	(1,629)	(1,624)	(3,302)	(3,205)
Other, net	(317)	(256)	(1,858)	(1,032)
Total other income (expenses)	(72,285)	(74,168)	(145,375)	(149,590)
Income before income taxes	181,489	167,719	294,495	256,530
Provision for income taxes	72,190	66,456	117,073	97,624
Net income	109,299	101,263	177,422	158,906
Pension plan amortized to periodic benefit cost:
Prior service cost, net of tax of $26 and $27 for the three months and $53 and $55 for the six months, respectively	42	44	83	87
Actuarial loss, net of tax of $(5) and $1,425 for the three months and $(10) and $2,849 for the six months, respectively	(8)	2,227	(15)	4,455
Foreign currency translation adjustment	446	(453)	(104)	(819)
Other comprehensive income (loss)	480	1,818	(36)	3,723
Comprehensive income	109,779	103,081	177,386	162,629
Basic earnings per share	$ 0.61	$ 0.57	$ 0.99	$ 0.89
Diluted earnings per share	$ 0.61	$ 0.57	$ 0.99	$ 0.89
Average common shares outstanding during the period
Basic	178,863	177,716	178,702	177,522
Diluted	179,693	178,910	179,512	178,716
Dividends declared per common share	$ 0.31	$ 0.28	$ 0.31	$ 0.28
Other Funds
Other income (expenses)
Allowance for funds used during construction	2,058	3,699	4,259	7,095
Borrowed Funds
Other income (expenses)
Allowance for funds used during construction	$ 1,271	$ 1,770	$ 2,754	$ 3,423