Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Reserve for returns and allowances on accounts receivable	$ 64,362	$ 106,680
Provision for doubtful accounts on accounts receivable	$ 4,120	$ 4,876
Common shares, no par value
Authorized common shares	500,000,000	500,000,000
Common shares, shares issued	145,532,978	141,007,461
5.25% Senior Notes [Member] | Senior Secured Second-Priority Notes [Member]
Coupon rate	5.25%	5.25%