Business Segments (Information on Operating and Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information, Profit (Loss):
Total revenues	$ 229,394	$ 232,154
Cost of sales	95,526	98,087
Gross profit	133,868	134,067
Advertising and marketing	27,750	34,801
Contribution margin	106,118	99,266
Other operating expenses	25,999	27,780
Operating income	80,119	71,486
North American OTC Healthcare
Segment Reporting Information, Profit (Loss):
Total revenues	210,658	210,784
International OTC Healthcare
Segment Reporting Information, Profit (Loss):
Total revenues	18,736	21,370
Operating Segments | North American OTC Healthcare
Segment Reporting Information, Profit (Loss):
Total revenues	210,658	210,784
Cost of sales	87,827	88,811
Gross profit	122,831	121,973
Advertising and marketing	24,680	31,014
Contribution margin	98,151	90,959
Operating Segments | International OTC Healthcare
Segment Reporting Information, Profit (Loss):
Total revenues	18,736	21,370
Cost of sales	7,699	9,276
Gross profit	11,037	12,094
Advertising and marketing	3,070	3,787
Contribution margin	7,967	8,307
Intersegment Eliminations | North American OTC Healthcare
Segment Reporting Information, Profit (Loss):
Total revenues	$ 1,000	$ 800