CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Operating revenues:
Oil and natural gas	$ 12,116		$ 14,717		$ 24,120		$ 31,502
Total operating revenues	757,276		659,316		1,435,444		1,326,355
Operating costs and expenses:
Contract drilling	255,318		242,748		506,377		489,820
Pressure pumping	241,977		188,280		441,785		356,436
Oil and natural gas	2,872		3,214		6,146		6,136
Depreciation, depletion, amortization and impairment	153,426		137,182		300,748		273,617
Selling, general and administrative	19,548		18,319		39,221		35,716
Net gain on asset disposals	(3,091)	[1]	(1,033)	[1]	(4,835)	[1]	(908)	[1]
Total operating costs and expenses	670,050		588,710		1,289,442		1,160,817
Operating income	87,226		70,606		146,002		165,538
Other income (expense):
Interest income	208		250		384		423
Interest expense, net of amount capitalized	(7,249)		(6,941)		(14,437)		(13,707)
Other	3		381		3		400
Total other expense	(7,038)		(6,310)		(14,050)		(12,884)
Income before income taxes	80,188		64,296		131,952		152,654
Income tax expense (benefit):
Current	25,680		2,335		52,615		9,908
Deferred	225		21,193		(9,768)		45,748
Total income tax expense	25,905		23,528		42,847		55,656
Net income	54,283		40,768		89,105		96,998
Net income per common share:
Basic	$ 0.37		$ 0.28		$ 0.62		$ 0.66
Diluted	$ 0.37		$ 0.28		$ 0.61		$ 0.66
Weighted average number of common shares outstanding:
Basic	143,622		145,465		143,259		145,148
Diluted	146,029		146,374		145,586		146,292
Cash dividends per common share	$ 0.10		$ 0.05		$ 0.20		$ 0.10
Contract Drilling
Operating revenues:
Oil and gas services	438,583		389,979		864,486		809,073
Pressure Pumping
Operating revenues:
Oil and gas services	$ 306,577		$ 254,620		$ 546,838		$ 485,780

[1] Net gains or losses associated with the disposal of assets relate to corporate strategy decisions of the executive management group. Accordingly, the related gains or losses have been separately presented and excluded from the results of specific segments.