CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES
Net income	$ 240,339	$ 93,779
Reconciliation of net income to cash provided by operating activities:
Depreciation, amortization and accretion	33,547	36,655
Amortization on debt issuance costs	221	0
Loss on extinguishment of debt	447	0
Bad debt expense	1,971	3,649
Deferred tax expense	5,094	13,772
Stock-based compensation	11,400	10,485
Employee stock purchase plan	140	106
Loss on disposal of property and equipment	87	332
Impairment of intangible and other long-lived assets	180	1,900
Restructuring charges	295	1,667
Changes in operating assets and liabilities:
Trade accounts receivable, net	(115,638)	(77,600)
Inventories, net	(54,373)	(97,458)
Prepaid expenses and other current assets	(19,808)	(9,075)
Income tax receivable	(357)	20,797
Other assets	3,493	(1,267)
Trade accounts payable	134,495	103,310
Accrued expenses	15,455	62,026
Income taxes payable	24,054	29,190
Long-term liabilities	(1,302)	60,828
Net cash provided by operating activities	279,740	253,096
INVESTING ACTIVITIES
Purchases of property and equipment	(21,832)	(21,409)
Proceeds from sale of property and equipment, net	68	7
Net cash used in investing activities	(21,764)	(21,402)
FINANCING ACTIVITIES
Proceeds from short-term borrowings	162,001	214,751
Repayments of short-term borrowings	(161,621)	(214,889)
Loan origination costs on short-term borrowings	(1,292)	0
Proceeds on issuance of stock for employee stock purchase plan	474	353
Cash paid for repurchase of common stock	(161,395)	(24,687)
Cash paid for shares withheld for taxes	(4,900)	(7,716)
Repayment of mortgage principal	(425)	(404)
Net cash used in financing activities	(167,158)	(32,592)
Effect of foreign currency exchange rates on cash	(4,850)	2,136
Net change in cash and cash equivalents	85,968	201,238
Cash and cash equivalents at beginning of period	429,970	291,764
Cash and cash equivalents at end of period	515,938	493,002
Cash paid (refunded) during the period for:
Income taxes, net of refunds and payments of $3,674 and $10,261, as of December 31, 2018 and 2017, respectively	29,646	(11,989)
Income tax refunds	(3,674)
Income tax payments		10,261
Interest	3,158	3,156
Non-cash investing activity:
Accrued for purchases of property and equipment	798	1,677
Accrued for purchases of property and equipment	$ 4,710	$ 853