Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Expense (Benefit) [Line Items]
Tax benefit from exercise of stock options	$ 13,700,000	$ 36,200,000	$ 16,000,000
Deferred tax assets on state net operating losses	13,000,000	16,400,000
State loss carryforwards expiration period	Mar. 31, 2034
Undistributed earnings of foreign subsidiaries	106,000,000
Unrecognized net income tax benefits	18,224,000	16,467,000	14,146,000
Deferred tax assets associated with unrecognized tax benefits	7,700,000
Unrecognized tax benefits, income tax penalties and interest expense, immaterial for period	Interest and penalties recognized for the year ended March 31, 2014 were classified as income tax expense in the Company’s consolidated statement of earnings and were not material.	Interest and penalties recognized for the year ended March 31, 2013 were classified as income tax expense in the Company’s consolidated statement of earnings and were not material.	Interest and penalties recognized for the year ended March 31, 2012 were classified as income tax expense in the Company’s consolidated statement of earnings and were not material.
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	4,800,000	4,600,000
Other Noncurrent Liabilities [Member]
Income Tax Expense (Benefit) [Line Items]
Unrecognized net income tax benefits	$ 18,200,000