TOPIC 606 ADOPTION IMPACT AND REVENUE FROM CONTRACTS WITH CUSTOMERS: Impact of changes in accounting policies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2018	Apr. 01, 2018	Mar. 31, 2018
ASSETS
Deferred income taxes	$ 149		$ 149				$ 10,703
Deferred commissions, net	9,478		9,478				0
Others	1,917,891		1,917,891
Total assets	1,927,518		1,927,518				1,209,497
Liabilities
Total liabilities	567,902		567,902
Equity
Retained earnings	1,715,066		1,715,066				628,331
Other equity	(355,450)		(355,450)
Total equity	1,359,616		1,359,616				749,095
TOTAL LIABILITIES AND EQUITY	1,927,518		1,927,518				$ 1,209,497
Income Statement [Abstract]
Revenues	80,021	$ 59,121	207,304	$ 159,891
Cost of revenue	34,838	24,526	82,958	72,596
Gross profit	45,183	34,595	124,346	87,295
Operating expenses:
Sales and marketing	40,054	27,832	109,317	77,904
Other operating expenses			131,041
Total operating expenses	93,394	62,284	240,358	192,936
Loss from operations	(48,211)	(27,689)	(116,012)	(105,641)
Total other income	10,404	432	10,479	115
Loss from continuing operations before income taxes	(37,807)	(27,257)	(105,533)	(105,526)
Income taxes (benefit)	(22,546)	(29,791)	(21,274)	(54,980)
Net loss from continuing operations	(15,261)	2,534	(84,259)	(50,546)
Statement of Comprehensive Income [Abstract]
Net loss	1,056,400	22,941	1,074,008	18,305
Other comprehensive income (loss):
Change in foreign currency translation adjustment	(2,301)	416	(2,876)	1,827
Comprehensive loss	1,054,099	23,357	1,071,132	20,132
Cash flows from operating activities:
Earnings from discontinued operations, net of tax	(1,071,661)	(20,407)	(1,158,267)	(68,851)
Adjustments to reconcile net earnings to net cash used in operating activities:
Deferred income taxes			20,723	(19,425)
Others			91,425
Changes in operating assets and liabilities:
Accounts receivable, net			(35,011)	(9,818)
Deferred commissions			(3,035)	0
Other assets			654	2,365
Accounts payable and other liabilities			(29,274)	1,786
Deferred Revenue			(1,555)	(439)
Net cash used in operating activities			(40,332)	(4,755)
Net cash from investing activities			(7,795)	(3,969)
Net cash from financing activities			(820,644)	(35,067)
Net cash provided by discontinued operations			2,277,338	50,610
Effect of exchange rate changes on cash			(1,811)	868
Net change in cash and cash equivalents			1,406,756	7,687
Cash and cash equivalents at beginning of period	1,546,774		140,018	168,680
Cash and cash equivalents at end of period	1,546,774	$ 176,367	1,546,774	$ 176,367
ASC 606 Adjustments | Accounting Standards Update 2014-09
ASSETS
Deferred income taxes					$ 2,256
Deferred commissions, net	(9,478)		(9,478)
Others	0		0
Total assets	(7,222)		(7,222)
Liabilities
Total liabilities	0		0
Equity
Retained earnings	(7,222)		(7,222)			$ 12,700
Other equity	0		0
Total equity	(7,222)		(7,222)
TOTAL LIABILITIES AND EQUITY	(7,222)		(7,222)
Income Statement [Abstract]
Revenues			0
Cost of revenue			0
Gross profit			0
Operating expenses:
Sales and marketing			3,035
Other operating expenses			0
Total operating expenses			3,035
Loss from operations			(3,035)
Total other income			0
Loss from continuing operations before income taxes			(3,035)
Income taxes (benefit)			(722)
Net loss from continuing operations			(2,313)
Statement of Comprehensive Income [Abstract]
Net loss			(2,313)
Other comprehensive income (loss):
Change in foreign currency translation adjustment			0
Comprehensive loss			(2,313)
Cash flows from operating activities:
Earnings from discontinued operations, net of tax			0
Adjustments to reconcile net earnings to net cash used in operating activities:
Deferred income taxes			(722)
Others			0
Changes in operating assets and liabilities:
Accounts receivable, net			0
Deferred commissions			3,035
Other assets			0
Accounts payable and other liabilities			0
Deferred Revenue			0
Net cash used in operating activities			0
Net cash from investing activities			0
Net cash from financing activities			0
Net cash provided by discontinued operations			0
Effect of exchange rate changes on cash			0
Net change in cash and cash equivalents			0
Cash and cash equivalents at beginning of period	0		0
Before ASC topic 606
ASSETS
Deferred income taxes					$ 2,405
Deferred commissions, net	0		0
Others	1,917,891		1,917,891
Total assets	1,920,296		1,920,296
Liabilities
Total liabilities	567,902		567,902
Equity
Retained earnings	1,707,844		1,707,844
Other equity	(355,450)		(355,450)
Total equity	1,352,394		1,352,394
TOTAL LIABILITIES AND EQUITY	1,920,296		1,920,296
Income Statement [Abstract]
Revenues			207,304
Cost of revenue			82,958
Gross profit			124,346
Operating expenses:
Sales and marketing			112,352
Other operating expenses			131,041
Total operating expenses			243,393
Loss from operations			(119,047)
Total other income			10,479
Loss from continuing operations before income taxes			(108,568)
Income taxes (benefit)			(21,996)
Net loss from continuing operations			(86,572)
Statement of Comprehensive Income [Abstract]
Net loss			1,071,695
Other comprehensive income (loss):
Change in foreign currency translation adjustment			(2,876)
Comprehensive loss			1,068,819
Cash flows from operating activities:
Earnings from discontinued operations, net of tax			(1,158,267)
Adjustments to reconcile net earnings to net cash used in operating activities:
Deferred income taxes			20,001
Others			91,425
Changes in operating assets and liabilities:
Accounts receivable, net			(35,011)
Deferred commissions			0
Other assets			654
Accounts payable and other liabilities			(29,274)
Deferred Revenue			(1,555)
Net cash used in operating activities			(40,332)
Net cash from investing activities			(7,795)
Net cash from financing activities			(820,644)
Net cash provided by discontinued operations			2,277,338
Effect of exchange rate changes on cash			(1,811)
Net change in cash and cash equivalents			1,406,756
Cash and cash equivalents at beginning of period	$ 1,546,774		$ 140,018