CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents	$ 20,362	$ 16,557
Restricted cash	29,662	6,896
Accounts receivable, net	163,479	174,913
Inventories	55,094	55,609
Regulatory assets	47,374	37,719
Deferred income taxes	20,843	14,301
Other	14,071	14,961
Total current assets	350,885	320,956
Property, plant, and equipment, net	3,758,008	2,690,128
Goodwill	355,128	355,128
Regulatory assets	455,757	316,952
Other noncurrent assets	54,165	32,096
Total assets	4,973,943	3,715,260
Current Liabilities:
Current maturities of capital leases	1,730	1,662
Short-term borrowings	267,840	140,950
Accounts payable	81,961	92,957
Accrued expenses	206,882	181,613
Regulatory liabilities	56,169	46,406
Total current liabilities	614,582	463,588
Long-term capital leases	28,162	29,895
Long-term debt	1,662,099	1,155,097
Deferred income taxes	446,600	395,333
Noncurrent regulatory liabilities	362,228	348,053
Other noncurrent liabilities	382,489	292,624
Total liabilities	3,496,160	2,684,590
Commitments and Contingencies (Note 20)
Shareholders' Equity:
Common stock, par value $0.01; authorized 200,000,000 shares; issued and outstanding 50,522,280 and 46,914,811 respectively; Preferred stock, par value $0.01; authorized 50,000,000 shares; none issued	505	423
Treasury stock at cost	(92,558)	(91,744)
Paid-in capital	1,313,844	910,184
Retained earnings	264,758	209,091
Accumulated other comprehensive income	(8,766)	2,716
Total shareholders' equity	1,477,783	1,030,670
Total liabilities and shareholders' equity	$ 4,973,943	$ 3,715,260