Income Taxes (Unrecognized Net Income Tax Benefits) (Details) (USD $)	12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Mar. 31, 2011
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized net income tax benefits at period start date	$ 14,146,000	[1]	$ 11,443,000	[1]
Additions for current year tax positions	2,419,000		2,755,000	[1]
Additions for tax positions of prior years	969,000		0	[1]
Reductions for tax positions of prior years	(1,067,000)		0	[1]
Reductions for settlements with taxing authorities	0		0	[1]
Reductions as a result of expiration of applicable statutes of limitations	0		(52,000)	[1]
Unrecognized net income tax benefits at period end date	16,467,000		14,146,000	[1]
Unrecognized Tax Benefits [Line Items]
Unrecognized Tax Benefits, Interest Expense Accrued			4,000,000		3,200,000
Unrecognized net income tax benefits	16,467,000		14,146,000	[1]
Other non-current assets [Member]
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized net income tax benefits at period start date					5,100,000
Unrecognized net income tax benefits at period end date	7,100,000		6,200,000		5,100,000
Unrecognized Tax Benefits [Line Items]
Unrecognized net income tax benefits	$ 7,100,000		$ 6,200,000		$ 5,100,000

[1] The Company modified the presentation of its unrecognized net income tax benefits for fiscal 2012 and 2011 from a presentation inclusive of $4.0 million and $3.2 million of potential interest associated with uncertain tax positions and net of $6.2 million and $5.1 million of federal tax assets associated with the unrecognized state tax benefits, respectively, to conform to the current presentation of the unrecognized state tax benefits on a gross basis.