Summary Financial Information (Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Net sales									$ 839,419	$ 637,123	$ 597,103
Cost of products sold									554,845	444,191	409,840
Gross profit	$ 74,602	$ 69,045	$ 71,619	$ 69,308	$ 50,335	$ 44,821	$ 49,729	$ 48,047	284,574	192,932	187,263
Selling expenses									101,956	77,319	72,858
General and administrative expenses									83,350	69,928	61,418
Amortization of intangibles									15,552	8,105	5,024
Income from operations	$ 16,324	$ 14,173	$ 19,587	$ 20,015	$ (3,164)	$ 5,317	$ 12,619	$ 11,201	70,099	25,973	40,570
Interest and debt expense									19,733	10,966	7,904
Investment (income) loss, net									(157)	(462)	(796)
Foreign currency exchange loss (gain), net									1,539	1,232	2,215
Other (income) expense, net									(701)	(93)	(377)
Income from continuing operations before income tax expense									49,685	13,027	31,624
Income tax expense									27,620	4,043	12,045
Net income									$ 22,065	$ 8,984	$ 19,579