Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011
Trade receivables, allowances for doubtful accounts	$ 30,624	$ 23,655
Preferred stock, shares authorized	20,030	20,030
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000	200,000
Common Stock [Member]
Common stock, shares issued	86,801	86,591
Treasury Stock [Member]
Treasury stock, shares	10,611	6,995