Significant Accounting Policies (Net Income Per Share) (Options and Rights Excluded) (Details) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Anti-dilutive shares	969	508	1,126
Employee stock options
Anti-dilutive shares	953	435	1,093
Stock purchase rights
Anti-dilutive shares	16	73	33