Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 480,181	$ 437,100
Accounts receivable - Trade, net of allowance for uncollectible accounts of $6,121 and $5,152, respectively	150,625	152,233
Unbilled revenue	25,057	26,992
Costs in excess of billing	2,529	6,848
Other current assets	80,480	96,934
Current assets of discontinued operations		84,000
Total current assets	738,872	804,107
Property and equipment	1,913,000	2,051,796
Less accumulated depreciation	(411,320)	(565,921)
Property and equipment, net	1,501,680	1,485,875
Other assets:
Equity investments	161,200	167,599
Goodwill	62,815	62,935
Other assets, net	47,339	49,837
Non-current assets of discontinued operations		816,227
Total assets	2,511,906	3,386,580
Current liabilities:
Accounts payable	75,035	92,398
Accrued liabilities	83,359	161,514
Income tax payable	18,946
Current maturities of long-term debt	20,376	16,607
Current liabilities of discontinued operations		182,527
Total current liabilities	197,716	453,046
Long-term debt	548,204	1,002,621
Deferred tax liabilities	260,649	359,237
Other non-current liabilities	18,274	5,025
Non-current liabilities of discontinued operations		147,237
Total liabilities	1,024,843	1,967,166
Commitments and contingencies
Shareholders' equity:
Common stock, no par, 240,000 shares authorized, 105,794 and 105,763 shares issued, respectively	937,501	932,742
Retained earnings	549,729	476,310
Accumulated other comprehensive loss	(25,502)	(15,667)
Total controlling interest shareholders' equity	1,461,728	1,393,385
Noncontrolling interests	25,335	26,029
Total equity	1,487,063	1,419,414
Total liabilities and shareholders' equity	$ 2,511,906	$ 3,386,580