Segment Reporting and Significant Customer Information - Operating Results from Continuing Operations and Assets by Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues from External Customers and Long-Lived Assets
Revenues	$ 20,327	$ 29,160
Operating profit (loss)	(5,340)	6,570
North America
Revenues from External Customers and Long-Lived Assets
Revenues	12,697	18,587
Operating profit (loss)	(976)	4,463
Europe
Revenues from External Customers and Long-Lived Assets
Revenues	6,947	10,573
Operating profit (loss)	(1,341)	2,137
Jack’s Flight Club
Revenues from External Customers and Long-Lived Assets
Revenues	683	0
Operating profit (loss)	(3,015)	0
Elimination
Revenues from External Customers and Long-Lived Assets
Revenues	0	0
Operating profit (loss)	(8)	(30)
Operating Segments | North America
Revenues from External Customers and Long-Lived Assets
Revenues	12,549	18,136
Operating Segments | Europe
Revenues from External Customers and Long-Lived Assets
Revenues	7,103	11,054
Operating Segments | Jack’s Flight Club
Revenues from External Customers and Long-Lived Assets
Revenues	683	0
Operating Segments | Elimination
Revenues from External Customers and Long-Lived Assets
Revenues	(8)	(30)
Intersegment revenues (expenses) | North America
Revenues from External Customers and Long-Lived Assets
Revenues	148	451
Intersegment revenues (expenses) | Europe
Revenues from External Customers and Long-Lived Assets
Revenues	(156)	(481)
Intersegment revenues (expenses) | Jack’s Flight Club
Revenues from External Customers and Long-Lived Assets
Revenues	0	0
Intersegment revenues (expenses) | Elimination
Revenues from External Customers and Long-Lived Assets
Revenues	$ 8	$ 30