Goodwill - Changes in Carrying Amount of Goodwill (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Balance at beginning of the period	$ 35,384,000	$ 35,384,000	$ 43,208,000
Adjustments to goodwill for foreign currency translation		(301,000)	464,000
Impairment	0	0	(8,288,000)	$ 0
Goodwill Ending Balance		35,083,000	35,384,000	43,208,000
U.S. and Canada
Goodwill [Line Items]
Balance at beginning of the period	23,804,000	23,804,000	29,540,000
Adjustments to goodwill for foreign currency translation		(203,000)	317,000
Impairment			(6,100,000)
Goodwill Ending Balance		23,601,000	23,804,000	29,540,000
International
Goodwill [Line Items]
Balance at beginning of the period	11,580,000	11,580,000	11,455,000
Adjustments to goodwill for foreign currency translation		(98,000)	125,000
Impairment			0
Goodwill Ending Balance		11,482,000	11,580,000	11,455,000
Halloween
Goodwill [Line Items]
Balance at beginning of the period	$ 0	0	2,213,000
Adjustments to goodwill for foreign currency translation		0	22,000
Impairment			(2,200,000)
Goodwill Ending Balance		$ 0	$ 0	$ 2,213,000