Impairment of Inventory and Long-Lived Assets - Schedule of asset impairment charges (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Inventories		$ 16,600,000	$ 18,000,000
Property and equipment	$ 0	14,600,000	2,300,000
Total Impairment	$ 0	40,435,000	20,372,000	$ 40,435,000	$ 20,372,000
Drilling Technologies [Member]
Segment Reporting Information [Line Items]
Inventories		12,653,000	17,241,000
Property and equipment		14,642,000	2,327,000
Intangible assets other than goodwill		9,227,000	0
Production Technologies [Member]
Segment Reporting Information [Line Items]
Inventories		$ 3,913,000	$ 804,000