Condensed Consolidated Balance Sheets (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 414,189	$ 391,085
Accounts receivable - Trade, net of allowance for uncollectible accounts of $4,395 and $4,527, respectively	212,406	177,293
Unbilled revenue	18,325	33,712
Costs in excess of billing	1,978	15,699
Other current assets	110,334	123,065
Total current assets	757,232	740,854
Property and equipment	4,586,583	4,486,077
Less - accumulated depreciation	(2,111,273)	(1,958,997)
Property and equipment, net	2,475,310	2,527,080
Other assets:
Equity investments	188,772	187,031
Goodwill	62,902	62,494
Other assets, net	76,421	74,561
Total assets	3,560,637	3,592,020
Current liabilities:
Accounts payable	148,142	159,381
Accrued liabilities	190,226	198,237
Current maturities of long-term debt	7,759	10,179
Total current liabilities	346,127	367,797
Long-term debt	1,239,893	1,347,753
Deferred income taxes	431,821	413,639
Asset retirement obligations	166,458	170,410
Other long-term liabilities	5,432	5,777
Total liabilities	2,189,731	2,305,376
Convertible preferred stock	1,000	1,000
Commitments and contingencies
Shareholders' equity:
Common stock, no par, 240,000 shares authorized, 105,948 and 105,592 shares issued, respectively	911,393	906,957
Retained earnings	459,875	392,705
Accumulated other comprehensive loss	(27,956)	(39,058)
Total controlling interest shareholders' equity	1,343,312	1,260,604
Noncontrolling interests	26,594	25,040
Total equity	1,369,906	1,285,644
Total liabilities and shareholders' equity	$ 3,560,637	$ 3,592,020