Industry Segment Information (Revenue From Different Segments) (Details) (USD $)	3 Months Ended										12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting [Abstract]
Oil and natural gas											$ 649,718,000		$ 567,944,000		$ 514,614,000
Contract drilling											479,091,000		579,368,000		536,872,000
Elimination of inter-segment revenue											(64,313,000)		(49,649,000)		(52,221,000)
Contract drilling net of inter-segment revenue											414,778,000		529,719,000		484,651,000
Gas gathering and processing											378,397,000		290,773,000		284,248,000
Elimination of inter-segment revenue											(91,043,000)		(73,313,000)		(76,010,000)
Gas gathering and processing											287,354,000		217,460,000		208,238,000
Total revenues	359,121,000		333,776,000	340,421,000	318,532,000	331,582,000		321,790,000	327,785,000	333,966,000	1,351,850,000		1,315,123,000		1,207,503,000
Oil and natural gas											239,219,000		(77,221,000)	[1]	199,993,000
Contract drilling											96,304,000		159,188,000		135,085,000
Gas gathering and processing											10,757,000		5,780,000	[2]	17,278,000
Total operating income											346,280,000	[3]	87,747,000	[3]	352,356,000	[3]
General and administrative expense											(38,323,000)		(33,086,000)		(30,055,000)
Gain (Loss) on Disposition of Assets											17,076,000		253,000		(595,000)
Interest expense, net											(15,015,000)		(14,137,000)		(4,167,000)
Gain (loss) on derivatives not designated as hedges and hedge ineffectiveness, net											(8,374,000)		(1,243,000)		1,702,000
Other Income (loss), net											(175,000)		(132,000)		(239,000)
Income before income taxes											301,469,000		39,402,000		319,002,000
Oil and natural gas	2,441,792,000					2,214,029,000					2,441,792,000		2,214,029,000		1,820,492,000
Contract drilling	1,042,661,000					1,079,736,000					1,042,661,000		1,079,736,000		1,118,666,000
Gas gathering and processing	473,717,000					413,708,000					473,717,000		413,708,000		247,763,000
Total identifiable assets	3,958,170,000	[4]				3,707,473,000	[4]				3,958,170,000	[4]	3,707,473,000	[4]	3,186,921,000	[4]
Corporate assets	64,220,000					53,647,000					64,220,000		53,647,000		69,799,000
Total assets	4,022,390,000					3,761,120,000					4,022,390,000		3,761,120,000		3,256,720,000
Oil and natural gas											531,233,000	[5]	1,145,337,000	[5]	588,158,000	[5]
Contract drilling											64,325,000		77,520,000		162,208,000
Gas gathering and processing											96,085,000		183,162,000		79,355,000
Other											4,483,000	[5]	11,083,000	[5]	2,688,000	[5]
Total capital expenditures											696,126,000		1,417,102,000		832,409,000
Oil and gas depreciation, depletion, and amortization											226,498,000		211,347,000		183,350,000
Impairment of Oil and Natural Gas Properties											0		283,606,000	[1]	0
Contract drilling											71,194,000		81,007,000		79,667,000
Gas gathering and processing											33,191,000		24,388,000	[2]	16,101,000
Other											3,024,000		2,279,000		1,333,000
Total depreciation, depletion, amortization and impairment											333,907,000		602,627,000		280,451,000
Non-cash write down of our oil and natural gas properties						167,700,000			115,900,000
Non-cash write down of our oil and natural gas properties net of tax						104,400,000			72,100,000
Impairment of long-lived assets held-for-use						1,200,000					0		1,200,000		0
Reclassified salt water disposal expenditures													$ 16,988,000		$ 8,103,000

[1] In June 2012 and December 2012, due to low 12-month average commodity prices, we incurred non-cash ceiling test write downs of our oil and natural gas properties of $115.9 million pre-tax ($72.1 million net of tax) and $167.7 million pre-tax ($104.4 million net of tax), respectively.

[2] Depreciation, depletion, amortization, and impairment for gas gathering and processing includes a $1.2 million write down of our Erick system.

[3] Operating income is total operating revenues less operating expenses, depreciation, depletion, amortization, and impairment and does not include general corporate expenses, (gain) loss on disposition of assets, gain (loss) on non-designated hedges and hedge ineffectiveness, interest expense, other income (loss), or income taxes.

[4] Identifiable assets are those used in Unit’s operations in each industry segment. Corporate assets are principally cash and cash equivalents, short-term investments, corporate leasehold improvements, furniture and equipment.

[5] Reclassified salt water disposal capital expenditures out of other and into oil and natural gas of $16,988 and $8,103 for 2012 and 2011, respectively.