Net Loss Per Share (Common Shares Reserved For Future Issuance) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2010
Shares reserved for future issuance	20,537	22,535
Stock Options [Member]
Stock options outstanding	3,310	3,310
Average exercise price on stock option	$ 9.75	9.75
Purchase Options and Restricted Shares [Member]
Share purchase options and restricted share units available for future issuance	3,534	3,683
October 2004 Notes [Member]
Coupon rate	2.9375%		2.9375%
Conversion price per share	$ 11.50
Shares reserved for future issuance	2,342	4,028
February 2005 Notes [Member]
Coupon rate	3.625%		3.625%
Conversion price per share	$ 14.28
Shares reserved for future issuance	1,643	1,643
April 2009 Notes [Member]
Coupon rate	3.625%		3.625%
Conversion price per share	$ 8.25
Shares reserved for future issuance	8,070	8,070
Restricted Share Units [Member]
Restricted share units - unvested	1,638	1,801

Aggregate number of common shares reserved for future issuance.

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The price per share of the conversion feature embedded in the debt instrument.

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Interest rate stated in the contractual debt agreement.

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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The weighted average price as of the beginning of the year at which grantees can acquire the shares reserved for issuance under the stock option plan.

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