CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
OPERATING ACTIVITIES:
Net Income	$ 83,517	$ 67,890
Items not affecting cash:
Depreciation and depletion	91,139	84,685
Amortization of debt issue costs, discount and deferred hedge gain	4,856	290
Amortization of restricted stock	2,238	1,826
Equity portion of allowance for funds used during construction	(4,393)	(3,572)
Gain on disposition of assets	(347)	(761)
Deferred income taxes	29,537	41,159
Changes in current assets and liabilities:
Restricted cash	(10,286)	(1,536)
Accounts receivable	55,388	14,500
Inventories	(7,357)	(8,462)
Other current assets	5,086	(1,983)
Accounts payable	(30,298)	(19,512)
Accrued expenses	26,257	22,358
Regulatory assets	(8,448)	9,384
Regulatory liabilities	6,207	(8,209)
Other noncurrent assets	(34,650)	(32,298)
Other noncurrent liabilities	(3,480)	5,579
Cash provided by operating activities	204,966	171,338
INVESTING ACTIVITIES:
Property, plant, and equipment additions	(186,085)	(153,951)
Change in restricted cash	(21,180)	0
Investment in New Market Tax Credit Program	(18,169)	0
Asset acquisitions	1,367	0
Proceeds from sale of assets	390	3,887
Cash used in investing activities	(223,677)	(150,064)
FINANCING ACTIVITIES:
Treasury stock activity	(881)	(1,107)
Proceeds from issuance of common stock, net	13,320	44,102
Dividends on common stock	(46,426)	(43,103)
Issuance of long-term debt	25,789	0
Repayments on long-term debt	(80)	(113)
Issuance (Repayments) of short-term borrowings, net	28,995	(19,954)
Financing costs	(832)	0
Cash provided by (used in) financing activities	19,885	(20,175)
Increase in Cash and Cash Equivalents	1,174	1,099
Cash and Cash Equivalents, beginning of period	16,557	9,822
Cash and Cash Equivalents, end of period	17,731	10,921
Cash paid during the period for:
Income taxes	28	47
Interest	44,170	40,873
Significant non-cash transactions:
Capital expenditures included in accounts payable and accrued expenses	$ 7,989	$ 11,245