Capital Stock (Share-Based Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Share-Based Compensation Expense [Line Items]
Total share-based compensation expense	$ 17,747		$ 9,749
Tax impact	(6,566)	[1]	0	[1]
Reduction in net income	11,181		9,749
Stock Options [Member]
Share-Based Compensation Expense [Line Items]
Total share-based compensation expense	3,767		299
Restricted Share Units and Other Share-based Compensation [Member]
Share-Based Compensation Expense [Line Items]
Total share-based compensation expense	7,403		7,224
Stock Appreciation Rights (SARs) [Member]
Share-Based Compensation Expense [Line Items]
Total share-based compensation expense	$ 6,577		$ 2,226

[1] Represents the income tax benefit recognized in the statements of operations for share-based compensation arrangements.