CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
OPERATING ACTIVITIES
Net income	$ 260,052	$ 240,339
Reconciliation of net income to net cash provided by (used in) operating activities:
Depreciation, amortization and accretion	29,437	33,547
Loss on extinguishment of debt	0	447
Bad debt expense	693	1,971
Deferred tax (benefit) expense	(1,020)	5,094
Stock-based compensation	12,766	11,540
Excess tax benefits from stock-based compensation	(1,755)	(1,319)
Loss on disposal of property and equipment	679	87
Impairment of operating lease assets and other long-lived assets	1,382	180
Restructuring charges	0	295
Changes in operating assets and liabilities:
Trade accounts receivable, net	(108,982)	(115,638)
Inventories, net	(87,104)	(54,373)
Prepaid expenses and other current assets	(19,970)	(19,808)
Income tax receivable	(5,781)	(357)
Net operating lease assets and liabilities	(1,692)
Other assets	(5,924)	3,714
Trade accounts payable	119,794	134,495
Other accrued expenses	21,504	15,455
Income taxes payable	23,545	25,373
Long-term liabilities	1,101	(1,302)
Net cash provided by operating activities	238,725	279,740
INVESTING ACTIVITIES
Purchases of property and equipment	(23,664)	(21,832)
Proceeds from sale of property and equipment	266	68
Net cash used in investing activities	(23,398)	(21,764)
FINANCING ACTIVITIES
Proceeds from short-term borrowings	69,336	162,001
Repayments of short-term borrowings	(63,178)	(161,621)
Debt issuance costs on short-term borrowings	0	(1,292)
Proceeds from issuance of stock	618	475
Proceeds from exercise of options	3,145	0
Repurchase of common stock	(190,405)	(161,395)
Cash paid for shares withheld for taxes	(5,995)	(4,900)
Repayments of mortgage principal	(448)	(425)
Net cash used in financing activities	(186,927)	(167,157)
Effect of foreign currency exchange rates on cash and cash equivalents	(1,228)	(4,851)
Net change in cash and cash equivalents	27,172	85,968
Cash and cash equivalents at beginning of period	589,692	429,970
Cash and cash equivalents at end of period	616,864	515,938
Cash paid during the period
Income taxes, net of refunds of $5,302 and $3,674, as of December 31, 2019 and 2018, respectively	47,482	29,646
Interest	1,749	3,158
Operating leases	45,732
Non-cash investing activities
Accrued for purchases of property and equipment	1,444	798
Accrued for asset retirement obligations	$ 38	$ 4,710