Business Segments (Information on Operating and Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information, Profit (Loss):
Net sales	$ 191,287	$ 144,541
Other revenues	845	1,161
Total revenues	192,132	145,702
Cost of sales	79,896	63,836
Gross profit	112,236	81,866
Advertising and promotion	26,422	19,096
Contribution margin	85,814	62,770
Other operating expenses	23,309	19,967
Operating income	62,505	42,803
Other expense	22,335	14,653
Income before income taxes	40,170	28,150
Provision for income taxes	13,997	11,418
Net income	$ 26,173	$ 16,732
Geographic Concentration Risk | Sales | United States
Geographic Areas, Revenues from External Customers [Abstract]
Concentration risk, percentage	87.30%	84.50%
Geographic Concentration Risk | Sales | Canada
Geographic Areas, Revenues from External Customers [Abstract]
Concentration risk, percentage	5.10%	5.60%
Geographic Concentration Risk | Sales | Australia
Geographic Areas, Revenues from External Customers [Abstract]
Concentration risk, percentage	5.70%	5.20%
Geographic Concentration Risk | Goodwill and Intangible Assets | United States
Geographic Areas, Revenues from External Customers [Abstract]
Concentration risk, percentage	95.60%
Geographic Concentration Risk | Goodwill and Intangible Assets | Australia
Geographic Areas, Revenues from External Customers [Abstract]
Concentration risk, percentage	4.40%
North American OTC Healthcare
Segment Reporting Information, Profit (Loss):
Net sales	$ 155,611	$ 110,256
Other revenues	40	177
Total revenues	155,651	110,433
Cost of sales	58,126	42,340
Gross profit	97,525	68,093
Advertising and promotion	23,195	16,353
Contribution margin	74,330	51,740
International OTC Healthcare
Segment Reporting Information, Profit (Loss):
Net sales	14,209	13,692
Other revenues	0	35
Total revenues	14,209	13,727
Cost of sales	5,290	5,078
Gross profit	8,919	8,649
Advertising and promotion	2,723	2,339
Contribution margin	6,196	6,310
Household Cleaning
Segment Reporting Information, Profit (Loss):
Net sales	21,467	20,593
Other revenues	805	949
Total revenues	22,272	21,542
Cost of sales	16,480	16,418
Gross profit	5,792	5,124
Advertising and promotion	504	404
Contribution margin	5,288	4,720
Operating Segments
Segment Reporting Information, Profit (Loss):
Net sales	192,015	145,258
Operating Segments | North American OTC Healthcare
Segment Reporting Information, Profit (Loss):
Net sales	156,339	110,973
Operating Segments | International OTC Healthcare
Segment Reporting Information, Profit (Loss):
Net sales	14,209	13,692
Operating Segments | Household Cleaning
Segment Reporting Information, Profit (Loss):
Net sales	21,467	20,593
Intersegment Eliminations
Segment Reporting Information, Profit (Loss):
Net sales	(728)	(717)
Intersegment Eliminations | North American OTC Healthcare
Segment Reporting Information, Profit (Loss):
Net sales	(728)	(717)
Intersegment Eliminations | International OTC Healthcare
Segment Reporting Information, Profit (Loss):
Net sales	0	0
Intersegment Eliminations | Household Cleaning
Segment Reporting Information, Profit (Loss):
Net sales	$ 0	$ 0