Consolidated Statements of Earnings (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 381,499	$ 376,315	$ 775,255	$ 742,436
Cost of Goods Sold	283,568	279,561	585,690	559,623
Gross Profit	97,931	96,754	189,565	182,813
Equity in Earnings of Unconsolidated Joint Venture	10,173	11,955	19,424	21,831
Corporate General and Administrative Expense	(9,922)	(9,821)	(17,925)	(19,500)
Litigation Settlements and Losses			(1,800)
Other Non-Operating Income	428	887	999	1,644
Interest Expense, Net	(6,817)	(7,456)	(13,449)	(14,939)
Earnings before Income Taxes	91,793	92,319	176,814	171,849
Income Taxes	(19,190)	(28,957)	(37,872)	(53,605)
Net Earnings	$ 72,603	$ 63,362	$ 138,942	$ 118,244
EARNINGS PER SHARE
Basic	$ 1.54	$ 1.32	$ 2.93	$ 2.46
Diluted	$ 1.53	$ 1.31	$ 2.90	$ 2.43
AVERAGE SHARES OUTSTANDING
Basic	47,219,532	48,053,733	47,453,655	48,087,625
Diluted	47,563,818	48,504,767	47,853,472	48,579,984
CASH DIVIDENDS PER SHARE	$ 0.10	$ 0.10	$ 0.20	$ 0.20