Supplementary Cash Flow Statement Information (Non-Cash Investing And Financing Activities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Non-cash investing activities:
Issuance of common shares related to Pilgrim Studios acquisition	$ 57,003
Investment in available-for-sale securities		$ 170,916
Investment in cost method investments	0	12,000	$ 0
Non-cash financing activities:
Accrued dividends	13,209	10,186	7,066
Accrued share repurchases	0	0	8,339
Convertible Senior Subordinated Notes
Non-cash financing activities:
Conversions of convertible senior subordinated notes	16,162	24,152	27,672
Available-for-sale Securities
Non-cash investing activities:
Investment in available-for-sale securities	0	158,916	0
Pilgrim Studios
Non-cash investing activities:
Issuance of common shares related to Pilgrim Studios acquisition	$ 57,003	$ 0	$ 0