UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current Assets
Cash and cash equivalents	$ 53,681	$ 38,316
Accounts receivable, net	25,538	25,824
Income taxes receivable	7,745	16,576
Materials and supplies	8,577	10,715
Prepaid expenses and other	5,626	5,580
Deferred income taxes	1,169	963
Total current assets	102,336	97,974
Investments, including $2,544 and $2,528 carried at fair value	9,463	9,332
Property, plant and equipment, net	405,729	408,963
Other Assets
Intangible assets, net	69,991	70,816
Deferred charges and other assets, net	9,076	9,921
Net other assets	79,067	80,737
Total assets	596,595	597,006
Current Liabilities
Current maturities of long-term debt	11,500	5,750
Accounts payable	5,727	12,604
Advanced billings and customer deposits	12,042	11,661
Accrued compensation	2,633	4,192
Accrued liabilities and other	9,242	9,787
Total current liabilities	41,144	43,994
Long-term debt, less current maturities	218,500	224,250
Other Long-Term Liabilities
Deferred income taxes	72,202	74,547
Deferred lease payable	6,393	6,156
Asset retirement obligations	6,611	6,485
Other liabilities	8,137	7,259
Total other liabilities	93,343	94,447
Commitments and Contingencies
Shareholders' Equity
Common stock	27,783	26,759
Accumulated other comprehensive income	2,247	2,594
Retained earnings	213,578	204,962
Total shareholders' equity	243,608	234,315
Total liabilities and shareholders' equity	$ 596,595	$ 597,006