Segment Information (Schedule of Segment Reporting Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Identifiable assets	$ 1,171,589				$ 1,229,623				$ 1,171,589	$ 1,229,623	$ 1,339,776
Revenues	283,110	273,267	259,812	239,034	238,183	243,979	248,354	229,670	1,055,223	960,186	919,443
Operating Costs									685,964	629,255	586,621
Drilling Services Revenue									516,473	528,327	498,867
Drilling Services Costs and Expenses									345,862	351,630	333,846
Production Services Revenue									538,750	431,859	420,576
Production Services Costs and Expenses									340,102	277,625	252,775
Segment Margin									369,259	330,931	332,822
Depreciation and amortization									183,376	187,918	164,717
Capital Expenditures									188,121	125,420	379,272
Drilling Services Segment [Member]
Segment Reporting Information [Line Items]
Identifiable assets	712,604				791,820				712,604	791,820	867,526
Segment Margin									170,611	176,697	165,021
Depreciation and amortization									115,714	122,201	108,151
Capital Expenditures									112,483	78,708	265,966
Production Services Segment [Member]
Segment Reporting Information [Line Items]
Identifiable assets	412,516				395,219				412,516	395,219	439,113
Segment Margin									198,648	154,234	167,801
Depreciation and amortization									66,326	64,604	55,693
Capital Expenditures									74,652	44,541	110,813
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Identifiable assets	46,469				42,584				46,469	42,584	33,137
Revenues									0	0	0
Operating Costs									0	0	0
Segment Margin									0	0	0
Depreciation and amortization									1,336	1,113	873
Capital Expenditures									$ 986	$ 2,171	$ 2,493