Cost of Sales (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cost of Sales [Abstract]
Customs expense	$ 31,400	$ 0	$ 0	$ 31,355

A noncash adjustment for the amount related to a ruling issued by the Tokyo District Court on a dispute between the Company and the customs authorities in Japan. The District Court upheld previous customs assessments related to the importation of several of the Company's products into Japan.

No definition available.

Name:	nus_CustomsExpense
Namespace Prefix:	nus_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration