Subsequent Events (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			1 Months Ended	3 Months Ended		1 Months Ended	2 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 31, 2013 drilling_rigs	Jun. 30, 2013 drilling_rigs	Mar. 31, 2012 drilling_rigs	Jan. 31, 2015 drilling_rigs	Feb. 17, 2015 drilling_rigs	Feb. 28, 2015	Feb. 17, 2015 drilling_rigs	Sep. 30, 2013 drilling_rigs	Feb. 01, 2015 drilling_rigs	Dec. 31, 2015 drilling_rigs	Mar. 31, 2015 drilling_rigs
Subsequent Event [Line Items]
Proceeds from sale of property and equipment	$ 8,370	$ 13,836	$ 3,093
Net property and equipment	856,541	937,657
Drilling Rigs [Member]
Subsequent Event [Line Items]
Drilling Rigs Held for Sale	9										8
Drilling Rigs [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Drilling Rigs Held for Sale												12
Drilling Services Segment [Member]
Subsequent Event [Line Items]
Segment Reporting Information, Disposed Drililng Rigs				8	2	2
Drilling Services Segment [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Segment Reporting Information, Disposed Drililng Rigs								6
Property, Plant and Equipment, Number of Real Estate Properties Sold							1	1
Proceeds from sale of property and equipment								17,800	17,800
Drilling Rigs												47
Estimated to Become classified as Held for Sale at end of Current Contract [Member] | Drilling Services Segment [Member]
Subsequent Event [Line Items]
Drilling Rigs on which Impairment Taken	15
Estimated to be Owned [Member] | Drilling Services Segment [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Drilling Rigs													43	38
Owned [Member] | Drilling Services Segment [Member]
Subsequent Event [Line Items]
Drilling Rigs	62
Owned [Member] | Drilling Services Segment [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Drilling Rigs												59
Active [Member] | Drilling Services Segment [Member]
Subsequent Event [Line Items]
Drilling Rigs	53
Active [Member] | Drilling Services Segment [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Drilling Rigs												47
Mechanical and Lower Horsepower Drilling Rigs [Member] | Drilling Services Segment [Member]
Subsequent Event [Line Items]
Drilling Rigs	31
Drilling Rigs Held for Sale	9
Drilling Rigs on which Impairment Taken	31
Mechanical and Lower Horsepower Drilling Rigs [Member] | Drilling Services Segment [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Segment Reporting Information, Disposed Drililng Rigs							3		6	3
Mechanical and Lower Horsepower Drilling Rigs [Member] | Estimated to Become classified as Held for Sale within 30 days at end of Current Contract [Member] | Drilling Services Segment [Member]
Subsequent Event [Line Items]
Drilling Rigs on which Impairment Taken	6
Mechanical and Lower Horsepower Drilling Rigs [Member] | Estimated to Become classified as Held for Sale in 30 to 90 Days at end of Current Contract [Member] | Drilling Services Segment [Member]
Subsequent Event [Line Items]
Drilling Rigs on which Impairment Taken	9
Mechanical and Lower Horsepower Drilling Rigs [Member] | Estimated to Become classified as Held for Sale at end of Current Contract [Member] | Drilling Services Segment [Member]
Subsequent Event [Line Items]
Drilling Rigs on which Impairment Taken	15
Drilling Rigs [Member] | Estimated to Become classified as Held for Sale at end of Current Contract [Member]
Subsequent Event [Line Items]
Net property and equipment	17,500
Drilling Rigs [Member] | Assets Held-for-sale [Member]
Subsequent Event [Line Items]
Net property and equipment	$ 9,100