Stock Based Compensation - Options Outstanding (Details) - $ / shares shares in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Number of Options
Outstanding Number of Options, Beginning (in shares)	1,222	1,269
Outstanding Number of Options, Expired (in shares)	(11)	(15)
Outstanding Number of Options, Forfeited (in shares)	(9)	(32)
Outstanding and Exercisable Number of Options, Ending (in shares)	1,202	1,222
Weighted Average Exercise Price
Outstanding Weighted Average Exercise Price, Beginning (in dollars per share)	$ 1.99	$ 1.98
Outstanding Weighted Average Exercise Price, Expired (in dollars per share)	2.42	1.52
Outstanding Weighted Average Exercise Price, Forfeited (in dollars per share)	1.87	1.83
Outstanding and Exercisable Weighted Average Exercise Price, Ending (in dollars per share)	$ 1.99	$ 1.99
Exercisable
Exercisable Number of Options, Beginning (in shares)	1,198	960
Exercisable Number of Options, Ending (in shares)	1,202	1,198
Exercisable Weighted Average Exercise Price, Beginning (in dollars per share)	$ 1.99	$ 1.99
Exercisable Weighted Average Exercise Price, Ending (in dollars per share)	$ 1.99	$ 1.99

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- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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- Definition

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(4)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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