Goodwill and Intangibles - Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 43,537	$ 43,297
Accumulated Amortization	(43,288)	(43,239)
Impairment	0	0
Net Carrying Amount	249	58
Customer Related
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	38,831	38,831
Accumulated Amortization	(38,831)	(38,831)
Impairment	0	0
Net Carrying Amount	0	0
Marketing Related
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,727	2,727
Accumulated Amortization	(2,718)	(2,709)
Impairment	0	0
Net Carrying Amount	9	18
Technology Related
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,979	1,739
Accumulated Amortization	(1,739)	(1,699)
Impairment	0	0
Net Carrying Amount	$ 240	$ 40

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

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