CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Statement of Financial Position [Abstract]
Trade accounts receivable, allowances (in dollars)	$ 37,802	$ 32,354
Inventory reserves	9,656	7,638
Accumulated depreciation	200,591	190,758
Accumulated amortization	$ 59,072	$ 54,361
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares (in shares)	125,000,000	125,000,000
Common stock, issued shares (in shares)	32,037,000	31,987,000
Common stock, outstanding shares (in shares)	32,037,000	31,987,000