CONDENSED CONSOLIDATED BALANCE SHEET (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents	$ 19,481	$ 16,557
Restricted cash	12,619	6,896
Accounts receivable, net	171,150	174,913
Inventories	38,079	55,609
Regulatory assets	45,333	37,719
Deferred income taxes	18,061	14,301
Other	12,194	14,961
Total current assets	316,917	320,956
Property, plant, and equipment, net	2,706,645	2,690,128
Goodwill	355,128	355,128
Regulatory assets	338,687	316,952
Other noncurrent assets	33,881	32,096
Total assets	3,751,258	3,715,260
Current Liabilities:
Current maturities of capital leases	1,661	1,662
Short-term borrowings	84,977	140,950
Accounts payable	68,697	92,957
Accrued expenses	215,513	181,613
Regulatory liabilities	48,356	46,406
Total current liabilities	419,204	463,588
Long-term capital leases	29,475	29,895
Long-term debt	1,155,103	1,155,097
Deferred income taxes	425,839	395,333
Noncurrent regulatory liabilities	350,810	348,053
Other noncurrent liabilities	296,510	292,624
Total liabilities	2,676,941	2,684,590
Commitments and Contingencies (Note 14)
Shareholders' Equity:
Common stock, par value $0.01; authorized 200,000,000 shares; issued and outstanding 42,751,270, and 39,135,645, respectively; Preferred stock, par value $0.01; authorized 50,000,000 shares; none issued	428	423
Treasury stock at cost	(92,756)	(91,744)
Paid-in capital	924,792	910,184
Retained earnings	239,217	209,091
Accumulated other comprehensive income	2,636	2,716
Total shareholders' equity	1,074,317	1,030,670
Total liabilities and shareholders' equity	$ 3,751,258	$ 3,715,260