Discontinued Operations and Business Realignment Costs - Components of Assets and Liabilities Related to Discontinued Operations (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets of discontinued operations	$ 100	$ 254
Current assets held for sale	879	0
Long-term assets of discontinued operations	431	0
Long-term liabilities of discontinued operations	0	(59)
Premium and Holiday Events Business | Discontinued Operations, Disposed of by Means Other than Sale, Abandonment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts receivable	81	62
Prepaid expenses and other current assets	19	192
Current assets of discontinued operations	100	254
Current assets held for sale	879	0
Long-term assets of discontinued operations	431	0
Long term assets held for sale	0	199
Accrued expenses and other current liabilities	(680)	(71)
Long-term liabilities of discontinued operations	0	(59)
Net assets	$ 730	$ 324