Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income	$ 37,283	$ 23,819	$ 20,567
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	2,126	1,369	770
Share based compensation	2,575	1,935	1,612
Deferred income taxes	(92)	1,951	(23)
Bad debt expense	112	421	260
(Increase) decrease in operating assets and increase (decrease) in liabilities:
Accounts receivable	(596)	(505)	(53)
Inventories - finished goods	(3,109)	5,358	(518)
Prepaid income taxes	(788)	243	(243)
Prepaid expenses and other current assets	137	1,416	(1,055)
Accounts payable	53	10,217	(149)
Accrued expenses and other current liabilities	337	321	(65)
Income taxes payable	(659)	659	(50)
Net cash provided by operating activities	37,379	47,204	21,053
Cash flows from investing activities:
Proceeds from sale of short term investments			15,591
Net change in investments			54
Purchases of property and equipment	(703)	(10,604)	(20,130)
Net cash used in investing activities	(703)	(10,604)	(4,485)
Cash flows from financing activities:
Dividends paid	(17,470)	(15,509)	(14,684)
Excess tax benefit related to stock compensation			142
Net cash used in financing activities	(17,470)	(15,509)	(14,542)
Net increase in cash and cash equivalents	19,206	21,091	2,026
Cash and cash equivalents, at beginning of year	58,730	37,639	35,613
Cash and cash equivalents, at end of year	77,936	58,730	37,639
Supplemental disclosure of cash flow information:
Cash paid for income taxes	18,046	11,373	12,173
Dividends payable in accrued expenses	$ 240	$ 217	$ 143