Segment Information (Schedule of Revenues from External Customers and Long-Lived Assets) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) drilling_rigs	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($) drilling_rigs	Dec. 31, 2015 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable assets	$ 786,525		$ 1,123,850	$ 821,993
Revenues	74,952		193,814
Impairment charges	0		5,990
Drilling Services Segment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable assets	$ 495,442		687,719
Drilling Rigs | drilling_rigs	31
Drilling Services Segment [Member] | Colombia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable assets	$ 48,729		135,184
Revenues	$ 1,096		$ 19,961
Drilling Rigs | drilling_rigs	8
Impairment charges		$ 60,200
Drilling Services Segment [Member] | Colombia [Member] | Assets Leased From Others [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling Rigs | drilling_rigs	3		3