Condensed Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 20,380	$ 86,197
Receivables:
Trade, net of allowance for doubtful accounts	128,950	106,084
Unbilled receivables	31,267	31,512
Insurance recoveries	5,693	5,470
Income taxes	1,583	2,168
Deferred income taxes	14,350	15,433
Inventory	13,211	11,184
Prepaid expenses and other current assets	13,333	11,564
Total current assets	228,767	269,612
Property and equipment, at cost	1,550,277	1,336,926
Less accumulated depreciation	610,832	542,970
Net property and equipment	939,445	793,956
Intangible assets, net of amortization	48,205	52,680
Goodwill	41,683	41,683
Noncurrent deferred income taxes	1,242	735
Other long-term assets	12,066	14,088
Total assets	1,271,408	1,172,754
Current liabilities:
Accounts payable	95,189	66,440
Current portion of long-term debt	871	872
Prepaid drilling contracts	4,071	3,966
Accrued expenses:
Payroll and related employee costs	24,965	29,057
Insurance premiums and deductibles	9,741	10,583
Insurance claims and settlements	5,580	5,470
Interest	12,269	12,283
Other	14,199	11,009
Total current liabilities	166,885	139,680
Long-term debt, less current portion	453,290	418,728
Noncurrent deferred income taxes	105,689	94,745
Other long-term liabilities	7,607	9,156
Total liabilities	733,471	662,309
Commitments and contingencies (Note 8)
Shareholders' equity:
Preferred stock, 10,000,000 shares authorized; none issued and outstanding	0	0
Common stock $.10 par value; 100,000,000 shares authorized; 61,880,310 shares and 62,018,191 shares outstanding at June 30, 2012 and December 31, 2011, respectively	6,215	6,188
Additional paid-in capital	445,985	442,020
Treasury stock, at cost; 134,188 shares and 95,409 shares at June 30, 2012 and December 31, 2011, respectively	(1,261)	(904)
Accumulated earnings	86,998	63,141
Total shareholders' equity	537,937	510,445
Total liabilities and shareholders' equity	$ 1,271,408	$ 1,172,754