Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014 segment		Sep. 30, 2013		Dec. 31, 2013
Segment Reporting [Abstract]
Number of reportable operating segments					2
Segment Information
Revenues	$ 119,283		$ 111,165		$ 373,783		$ 316,948
Depreciation, depletion and amortization	37,037	[1]	35,637	[1]	115,648	[1]	199,674	[1]
Other operating expenses	36,681	[2]	41,610	[2]	143,252	[2]	129,236	[2]
Interest expense	12,609		9,262		37,975		30,106
Other (income) expense	(10,035)		7,804		1,441		7,912
Income (loss) before income taxes	42,991		16,852		75,467		(49,980)
Income tax (expense) benefit	(15,562)		(5,901)		(27,319)		18,693
Net income (loss)	27,429		10,951		48,148		(31,287)
Total assets	1,450,546		1,379,710		1,450,546		1,379,710		1,366,737
Additions to property and equipment	117,312		65,759		306,771		203,937
Oil and Gas
Segment Information
Revenues	112,571		107,121		351,694		304,052
Depreciation, depletion and amortization	34,758	[1]	32,941	[1]	108,473	[1]	190,813	[1]
Other operating expenses	31,982	[2]	38,289	[2]	128,032	[2]	116,319	[2]
Interest expense	12,609		9,262		37,975		30,106
Other (income) expense	(10,035)		7,804		1,441		7,912
Income (loss) before income taxes	43,257		18,825		75,773		(41,098)
Income tax (expense) benefit	(14,907)		(6,414)		(26,263)		15,622
Net income (loss)	28,350		12,411		49,510		(25,476)
Total assets	1,420,998		1,352,645		1,420,998		1,352,645
Additions to property and equipment	112,135		64,775		289,914		200,949
Contract Drilling
Segment Information
Revenues	16,155		9,021		44,817		26,660
Depreciation, depletion and amortization	3,416	[1]	3,340	[1]	10,004	[1]	10,728	[1]
Other operating expenses	10,867	[2]	7,144	[2]	31,795	[2]	24,705	[2]
Interest expense	0		0		0		0
Other (income) expense	0		0		0		0
Income (loss) before income taxes	1,872		(1,463)		3,018		(8,773)
Income tax (expense) benefit	(655)		513		(1,056)		3,071
Net income (loss)	1,217		(950)		1,962		(5,702)
Total assets	66,555		54,524		66,555		54,524
Additions to property and equipment	7,315		1,494		20,181		3,097
Intercompany Eliminations
Segment Information
Revenues	(9,443)		(4,977)		(22,728)		(13,764)
Depreciation, depletion and amortization	(1,137)	[1]	(644)	[1]	(2,829)	[1]	(1,867)	[1]
Other operating expenses	(6,168)	[2]	(3,823)	[2]	(16,575)	[2]	(11,788)	[2]
Interest expense	0		0		0		0
Other (income) expense	0		0		0		0
Income (loss) before income taxes	(2,138)		(510)		(3,324)		(109)
Income tax (expense) benefit	0		0		0		0
Net income (loss)	(2,138)		(510)		(3,324)		(109)
Total assets	(37,007)		(27,459)		(37,007)		(27,459)
Additions to property and equipment	$ (2,138)		$ (510)		$ (3,324)		$ (109)

[1] Includes impairment of property and equipment.

[2] Includes the following expenses: production, exploration, midstream services, drilling rig services, accretion of asset retirement obligations, general and administrative and other operating expenses.