Segment Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 segment	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting [Abstract]
Number of reportable operating segments	2
Segment Information
Revenues	$ 468,456	$ 429,215	$ 423,052
Depreciation, depletion and amortization	166,383	240,713	148,631
Other operating expenses	190,434	175,887	194,628
Interest expense	50,907	43,079	38,664
Other (income) expense	(7,836)	6,826	(15,982)
Income (loss) before income taxes	68,568	(37,290)	57,111
Income tax (expense) benefit	(24,687)	12,428	(22,008)
Net income (loss)	43,881	(24,862)	35,103
Total assets	1,510,885	1,366,737	1,574,584
Additions to property and equipment	435,444	284,652	515,758
Oil and Gas
Segment Information
Revenues	440,428	411,403	407,194
Depreciation, depletion and amortization	157,164	229,460	140,967
Other operating expenses	170,878	159,294	176,922
Interest expense	50,907	43,079	38,664
Other (income) expense	(8,001)	6,826	(15,979)
Income (loss) before income taxes	69,480	(27,256)	66,620
Income tax (expense) benefit	(23,384)	9,136	(25,473)
Net income (loss)	46,096	(18,120)	41,147
Total assets	1,482,863	1,339,920	1,535,544
Additions to property and equipment	412,951	280,173	500,161
Contract Drilling
Segment Information
Revenues	59,107	37,255	57,218
Depreciation, depletion and amortization	13,307	13,844	14,442
Other operating expenses	41,912	32,817	52,678
Interest expense	0	0	0
Other (income) expense	165	0	(3)
Income (loss) before income taxes	3,723	(9,406)	(9,899)
Income tax (expense) benefit	(1,303)	3,292	3,465
Net income (loss)	2,420	(6,114)	(6,434)
Total assets	70,051	54,697	64,045
Additions to property and equipment	27,128	5,107	15,207
Intercompany Eliminations
Segment Information
Revenues	(31,079)	(19,443)	(41,360)
Depreciation, depletion and amortization	(4,088)	(2,591)	(6,778)
Other operating expenses	(22,356)	(16,224)	(34,972)
Interest expense	0	0	0
Other (income) expense	0	0	0
Income (loss) before income taxes	(4,635)	(628)	390
Income tax (expense) benefit	0	0	0
Net income (loss)	(4,635)	(628)	390
Total assets	(42,029)	(27,880)	(25,005)
Additions to property and equipment	$ (4,635)	$ (628)	$ 390