Business Segments, Concentration of Business, and Credit Risk and Significant Customers (Details 3) (USD $) In Thousands, unless otherwise specified	6 Months Ended				3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended	3 Months Ended
	Sep. 30, 2014 tannery	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2014 International Net Sales	Sep. 30, 2013 International Net Sales	Sep. 30, 2014 International Net Sales	Sep. 30, 2013 International Net Sales	Sep. 30, 2014 Net Trade Accounts Receivable	Mar. 31, 2014 Net Trade Accounts Receivable Customer One	Sep. 30, 2014 Net Trade Accounts Receivable Customer One	Mar. 31, 2014 Net Trade Accounts Receivable Customer Two	Sep. 30, 2014 US	Mar. 31, 2014 US	Sep. 30, 2014 All other countries	Mar. 31, 2014 All other countries
Business segment information
Property and equipment, by major country	$ 202,777	$ 184,570											$ 166,080	$ 148,178	$ 36,697	$ 36,392	[1]
Concentration risk (as a percent)	10.00%				39.80%	38.30%	39.10%	37.30%		11.80%	11.00%	11.40%
Concentration risk benchmark (as a percent)							10.00%		10.00%
Number of Tanneries	2
Cash and cash equivalents
Money market fund accounts	65,668	143,816
Cash	48,983	101,272
Total cash and cash equivalents	$ 114,651	$ 245,088	$ 84,107	$ 64,591

[1] No other country’s long-lived assets comprised more than 10% of total long-lived assets as of September 30, 2014 and March 31, 2014.