Intangible Assets and Related Accumulated Amortization (Detail) - USD ($)
$ in Thousands |
12 Months Ended |
|
Dec. 31, 2016 |
Dec. 31, 2015 |
| Intangible Assets And Goodwill [Line Items] |
|
|
| Intangible assets, gross |
$ 2,800
|
$ 2,800
|
| Intangible assets, accumulated amortization |
$ (2,800)
|
(2,749)
|
| Intangible assets, net |
|
51
|
| Useful life |
Indefinite life
|
|
| Goodwill gross |
$ 2,926
|
2,926
|
| Goodwill |
2,926
|
2,926
|
| Patents |
|
|
| Intangible Assets And Goodwill [Line Items] |
|
|
| Intangible assets, gross |
1,914
|
1,914
|
| Intangible assets, accumulated amortization |
$ (1,914)
|
(1,914)
|
| Patents | Minimum |
|
|
| Intangible Assets And Goodwill [Line Items] |
|
|
| Useful life |
4 years
|
|
| Patents | Maximum |
|
|
| Intangible Assets And Goodwill [Line Items] |
|
|
| Useful life |
10 years
|
|
| Trademarks |
|
|
| Intangible Assets And Goodwill [Line Items] |
|
|
| Useful life |
6 years
|
|
| Intangible assets, gross |
$ 69
|
69
|
| Intangible assets, accumulated amortization |
(69)
|
(69)
|
| Other Intangible Assets |
|
|
| Intangible Assets And Goodwill [Line Items] |
|
|
| Intangible assets, gross |
817
|
817
|
| Intangible assets, accumulated amortization |
$ (817)
|
(766)
|
| Intangible assets, net |
|
$ 51
|
| Other Intangible Assets | Minimum |
|
|
| Intangible Assets And Goodwill [Line Items] |
|
|
| Useful life |
4 years
|
|
| Other Intangible Assets | Maximum |
|
|
| Intangible Assets And Goodwill [Line Items] |
|
|
| Useful life |
6 years
|
|