Stockholders' Equity and Stock-Based Compensation Nonemployee Director Restricted Stock and Restricted Stock Unit Awards (Details) $ in Thousands	Dec. 31, 2016 USD ($)
Director Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock available for grant per employee	$ 135

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.

No definition available.

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