Stock-Based Compensation - SAR Awards Narrative (Details) - SARs - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award (in shares)	60,000	5,000
2017 SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award (in shares)		5,000
Resulting fair value per share (in dollars per share)		$ 4.10
Vesting period		2 years
2018 SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award (in shares)	60,000
Resulting fair value per share (in dollars per share)	$ 5.63
Vesting period	3 years 2 months 1 day
Share-based compensation expense	$ 0.1

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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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.

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Net number of non-option equity instruments granted to participants.

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