Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current Assets:
Cash	$ 2,874	$ 3,628
Short-term investments	89,750	150,072
Accounts receivable - net
Trade	95,952	84,768
Other	1,773	4,891
Inventories of spare parts - net	57,288	59,336
Other current assets	12,830	16,233
Income taxes receivable	925	558
Total current assets	261,392	319,486
Other	32,424	29,120
Property and equipment - net	672,937	596,533
Total assets	966,753	945,139
Current Liabilities:
Accounts payable	19,173	22,404
Accrued liabilities	26,631	28,319
Other current liabilities	45,800	0
Total current liabilities	91,604	50,723
Long-term debt	316,189	331,074
Deferred income taxes	80,790	81,988
Other long-term liabilities	7,550	8,938
Total liabilities	496,133	472,723
Commitments and contingencies (Note 3)
Shareholders' Equity:
Common stock	285	285
Additional paid-in capital	291,403	291,403
Accumulated other comprehensive loss	(10)	(162)
Retained earnings	177,696	179,644
Total shareholders' equity	470,620	472,416
Total liabilities and equity	966,753	945,139
Non-Voting Common Stock
Shareholders' Equity:
Common stock	1,246	1,246
Total shareholders' equity	$ 1,246	$ 1,246