Consolidated Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 13,032	$ 12,662
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	135,000,000	135,000,000
Common stock, shares issued (in shares)	54,590,184	54,370,810
Common stock, shares outstanding (in shares)	42,126,817	43,447,536
Treasury stock (in shares)	12,463,367	10,923,274