GOODWILL: (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2017 USD ($)
Goodwill
Goodwill at the beginning of year	$ 592,731
Change in foreign currency translation adjustment	30
Goodwill at the end of year	592,761
U.S.
Goodwill
Goodwill at the end of year	581,191
APAC
Goodwill
Goodwill at the end of year	11,570
Marketing Services
Goodwill
Goodwill at the beginning of year	118,890
Change in foreign currency translation adjustment	21
Goodwill at the end of year	118,911
Marketing Services | U.S.
Goodwill
Goodwill at the end of year	110,910
Marketing Services | APAC
Goodwill
Goodwill at the end of year	8,001
Audience Solutions
Goodwill
Goodwill at the beginning of year	273,448
Change in foreign currency translation adjustment	0
Goodwill at the end of year	273,448
Audience Solutions | U.S.
Goodwill
Goodwill at the end of year	273,448
Audience Solutions | APAC
Goodwill
Goodwill at the end of year	0
Connectivity
Goodwill
Goodwill at the beginning of year	200,393
Change in foreign currency translation adjustment	9
Goodwill at the end of year	200,402
Connectivity | U.S.
Goodwill
Goodwill at the end of year	196,833
Connectivity | APAC
Goodwill
Goodwill at the end of year	$ 3,569