Discontinued Operations - Summary Of Financial Information That Has Been Segregated From Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Discontinued Operations:
Gain (loss) from discontinued operations	$ (2,704)	$ (2,169)	$ (13,937)	$ (32,325)
Net loss from discontinued operations	(2,704)	(2,169)	(13,937)	(32,325)
Assets:
Assets held for sale	7,197		7,197		$ 43,900
Drilling Technologies | Discontinued Operations, Held-for-sale
Discontinued Operations:
Revenue	4,737	6,372	11,534	12,829
Cost of revenue	(2,603)	(4,155)	(7,259)	(9,587)
Selling, general and administrative	(2,740)	(3,495)	(5,771)	(8,155)
Depreciation and amortization	0	(337)	0	(1,085)
Research and development	(6)	(22)	(6)	(65)
Gain (loss) on disposal of long-lived assets	(12)	19	62	16
Impairment of inventory and long-lived assets	0	0	0	(36,522)
Loss from operations	(624)	(1,618)	(1,440)	(42,569)
Other expense	(46)	(69)	(117)	(243)
Gain (loss) from discontinued operations	(1,365)	0	(1,365)	0
Loss on write-down of assets held for sale	(272)	0	(6,831)	0
Loss before income taxes	(2,307)	(1,687)	(9,753)	(42,812)
Income tax benefit	158	456	3,147	14,881
Net loss from discontinued operations	(2,149)	(1,231)	(6,606)	(27,931)
Assets:
Accounts receivable, net	2,448		2,448		5,072
Inventories	1,942		1,942		9,078
Other current assets	1,595		1,595		278
Long-term receivable	0		0		0
Property and equipment, net	880		880		11,277
Goodwill	0		0		15,333
Other intangible assets, net	0		0		7,395
Assets held for sale	6,865		6,865		48,433
Valuation allowance	(904)		(904)		(18,971)
Assets held for sale, net	5,961		5,961		29,462
Liabilities:
Accounts payable	388		388		2,472
Accrued liabilities	1,607		1,607		1,190
Liabilities held for sale	1,995		1,995		3,662
Production Technologies | Discontinued Operations, Held-for-sale
Discontinued Operations:
Revenue	849	1,868	4,002	3,889
Cost of revenue	(707)	(1,882)	(3,189)	(3,793)
Selling, general and administrative	(802)	(897)	(1,675)	(2,051)
Depreciation and amortization	0	(149)	0	(298)
Research and development	(92)	(201)	(363)	(467)
Gain (loss) on disposal of long-lived assets	0	0	0	(59)
Impairment of inventory and long-lived assets	0	0	0	(3,913)
Loss from operations	(752)	(1,261)	(1,225)	(6,692)
Other expense	(16)	(23)	(52)	(44)
Gain (loss) from discontinued operations	171	0	171	0
Loss on write-down of assets held for sale	0	0	(9,718)	0
Loss before income taxes	(597)	(1,284)	(10,824)	(6,736)
Income tax benefit	42	346	3,493	2,342
Net loss from discontinued operations	(555)	$ (938)	(7,331)	$ (4,394)
Assets:
Accounts receivable, net	539		539		1,784
Inventories	0		0		8,115
Other current assets	697		697		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	1,236		1,236		20,599
Valuation allowance	0		0		(6,161)
Assets held for sale, net	1,236		1,236		14,438
Liabilities:
Accounts payable	40		40		914
Accrued liabilities	381		381		385
Liabilities held for sale	$ 421		$ 421		$ 1,299