Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Nov. 03, 2017	Mar. 31, 2017	Dec. 13, 2016
Net Investment Income [Line Items]
Held-to-maturity short-term investments	$ 0	$ 0	$ 0	$ 0		$ 19,931,000
Remaining amount of inventory acquired	16,249,000	21,322,000	16,249,000	21,322,000		18,187,000
Depreciation expense	$ 1,749,000	$ 1,216,000	$ 4,314,000	$ 3,863,000
Effective antidilutive securities excluded from computation of net income per share (in shares)	208	505	545	505
Commercial Paper
Net Investment Income [Line Items]
Held-to-maturity short-term investments						19,931,000
The McCall Pattern Company
Net Investment Income [Line Items]
Step up to fair value of inventory acquired							$ 21,773,000
Simplicity Creative Group
Net Investment Income [Line Items]
Step up to fair value of inventory acquired					$ 10,214,000
Depreciation expense	$ 20,000		$ 20,000
Machinery and equipment
Net Investment Income [Line Items]
Capital leased assets	564,000	$ 0	564,000	$ 0		$ 0
Capital leased assets, accumulated depreciation	$ 207,000		$ 207,000