Discontinued Operations - Summary Of Financial Information That Has Been Segregated From Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Discontinued Operations:
Gain (loss) from discontinued operations	$ 319	$ (876)	$ (13,621)	$ (33,200)
Net income (loss) from discontinued operations	319	(876)	(13,621)	(33,200)
Assets:
Assets held for sale	4,135		4,135		$ 43,900
Discontinued Operations, Held-for-sale | Drilling Technologies
Discontinued Operations:
Revenue	0	7,197	11,534	20,026
Cost of revenue	0	(4,290)	(7,259)	(13,876)
Selling, general and administrative	(791)	(3,568)	(6,562)	(11,723)
Depreciation and amortization	0	(340)	0	(1,425)
Research and development	0	0	(6)	(65)
Gain on disposal of long-lived assets	36	77	97	92
Impairment of inventory and long-lived assets	0	0	0	(36,522)
Loss from operations	(755)	(924)	(2,196)	(43,493)
Other income (expense)	26	(77)	(91)	(320)
Gain (loss) from discontinued operations	463	0	(902)	0
Loss on write-down of assets held for sale	0	0	(6,831)	0
Loss before income taxes	(266)	(1,001)	(10,020)	(43,813)
Income tax benefit	581	592	3,473	15,673
Net income (loss) from discontinued operations	315	(409)	(6,547)	(28,140)
Assets:
Accounts receivable, net	1,749		1,749		5,072
Inventories	5		5		9,078
Other current assets	1,585		1,585		278
Long-term receivable	0		0		0
Property and equipment, net	0		0		11,277
Goodwill	0		0		15,333
Other intangible assets, net	0		0		7,395
Assets held for sale	3,339		3,339		48,433
Valuation allowance	(109)		(109)		(18,971)
Assets held for sale, net	3,230		3,230		29,462
Liabilities:
Accounts payable	15		15		2,472
Accrued liabilities	1,419		1,419		1,190
Liabilities held for sale	1,434		1,434		3,662
Discontinued Operations, Held-for-sale | Production Technologies
Discontinued Operations:
Revenue	0	2,145	4,002	6,034
Cost of revenue	0	(2,040)	(3,189)	(5,833)
Selling, general and administrative	(64)	(878)	(1,739)	(2,929)
Depreciation and amortization	0	(149)	0	(447)
Research and development	0	(204)	(364)	(671)
Gain on disposal of long-lived assets	0	8	0	(51)
Impairment of inventory and long-lived assets	0	0	0	(3,913)
Loss from operations	(64)	(1,118)	(1,290)	(7,810)
Other income (expense)	0	(24)	(52)	(68)
Gain (loss) from discontinued operations	61	0	233	0
Loss on write-down of assets held for sale	0	0	(9,718)	0
Loss before income taxes	(3)	(1,142)	(10,827)	(7,878)
Income tax benefit	7	675	3,753	2,818
Net income (loss) from discontinued operations	4	$ (467)	(7,074)	$ (5,060)
Assets:
Accounts receivable, net	201		201		1,784
Inventories	5		5		8,115
Other current assets	699		699		370
Long-term receivable	0		0		4,179
Property and equipment, net	0		0		3,978
Goodwill	0		0		1,689
Other intangible assets, net	0		0		484
Assets held for sale	905		905		20,599
Valuation allowance	0		0		(6,161)
Assets held for sale, net	905		905		14,438
Liabilities:
Accounts payable	10		10		914
Accrued liabilities	142		142		385
Liabilities held for sale	$ 152		$ 152		$ 1,299