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