CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
OPERATING ACTIVITIES:
Net Income	$ 38,054	$ 51,425
Items not affecting cash:
Depreciation and depletion	39,890	35,819
Amortization of debt issue costs, discount and deferred hedge gain	979	287
Stock-based compensation costs	2,242	1,246
Equity portion of allowance for funds used during construction	(652)	(1,707)
Gain on disposition of assets	(55)	(88)
Deferred income taxes	4,890	9,007
Changes in current assets and liabilities:
Restricted cash	(197)	165
Accounts receivable	19,427	14,636
Inventories	6,825	7,057
Other current assets	(3,374)	1,004
Accounts payable	(11,303)	(23,179)
Accrued expenses	38,023	12,653
Regulatory assets	10,550	16,770
Regulatory liabilities	(2,971)	840
Other noncurrent assets	(1,485)	(782)
Other noncurrent liabilities	1,293	1,648
Cash Provided by Operating Activities	142,136	126,801
INVESTING ACTIVITIES:
Property, plant, and equipment additions	(51,318)	(56,538)
Proceeds from sale of assets	51	80
Change in restricted cash	0	4,806
Cash Used in Investing Activities	(51,267)	(51,652)
FINANCING ACTIVITIES:
Treasury stock activity	(1,788)	(1,991)
Dividends on common stock	(23,922)	(22,376)
Repayments on long-term debt	0	(7)
Repayments of short-term borrowings, net	(67,961)	(57,936)
Financing costs	(151)	(1,092)
Cash Used in Financing Activities	(93,822)	(83,402)
Decrease in Cash and Cash Equivalents	(2,953)	(8,253)
Cash and Cash Equivalents, beginning of period	11,980	20,362
Cash and Cash Equivalents, end of period	9,027	12,109
Cash (received) paid during the period for:
Income taxes	(2,948)	27
Interest	12,977	12,213
Significant non-cash transactions:
Capital expenditures included in trade accounts payable	$ 5,805	$ 6,395