SEGMENT INFORMATION: Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenues	$ 225,240	$ 217,267	$ 437,754	$ 432,068
Gross Profit	110,168	97,162	208,722	189,144
Operating Income (Loss)	453	7,120	(5,254)	15,282
Operating Segments
Segment Reporting Information [Line Items]
Revenues	225,240	217,267	437,754	432,068
Gross Profit	117,933	102,321	224,026	199,274
Operating Income (Loss)	57,086	51,472	105,364	97,004
Operating Segments | Marketing Services
Segment Reporting Information [Line Items]
Revenues	94,042	105,679	185,636	215,394
Gross Profit	34,320	34,480	65,678	71,946
Operating Income (Loss)	21,874	19,837	41,658	39,982
Operating Segments | Audience Solutions
Segment Reporting Information [Line Items]
Revenues	78,814	78,526	154,548	152,270
Gross Profit	48,321	47,998	95,531	89,910
Operating Income (Loss)	29,497	29,972	58,039	55,068
Operating Segments | Connectivity
Segment Reporting Information [Line Items]
Revenues	52,384	33,062	97,570	64,404
Gross Profit	35,292	19,843	62,817	37,418
Operating Income (Loss)	$ 5,715	$ 1,663	$ 5,667	$ 1,954