Condensed Consolidating Financials Condensed Comprehensive Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Comprehensive Income (Loss), Net of Tax	$ (10,402)	$ 3,178	$ (9,348)	$ (11,679)
Net Income (Loss) Attributable to Parent	33,770	38,916	63,713	60,794
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	23,368	42,094	54,365	49,115
Total revenues	211,800	176,038	412,302	337,291
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(12,653)	7,112	(9,238)	(8,125)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	2,251	(3,934)	(110)	(3,554)
j2 Global, Inc. [Member]
Other Comprehensive Income (Loss), Net of Tax	2,251	(267)	(110)	44
Net Income (Loss) Attributable to Parent	33,770	38,916	63,713	60,794
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	36,021	38,649	63,603	60,838
Total revenues	0	0	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	0	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	2,251	(267)	(110)	44
j2 Cloud Services, Inc. [Member]
Other Comprehensive Income (Loss), Net of Tax	0	(3,667)	0	(3,598)
Net Income (Loss) Attributable to Parent	38,019	45,530	72,342	71,782
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	38,019	41,863	72,342	68,184
Total revenues	66,254	56,547	122,639	111,166
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	0	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	(3,667)	0	(3,598)
Non-Guarantor Subsidiaries [Member]
Other Comprehensive Income (Loss), Net of Tax	(12,653)	7,112	(9,238)	(8,125)
Net Income (Loss) Attributable to Parent	20,786	26,742	48,482	50,283
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	8,133	33,854	39,244	42,158
Total revenues	166,079	129,217	321,645	245,652
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(12,653)	7,112	(9,238)	(8,125)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	0	0	0
Consolidation, Eliminations [Member]
Other Comprehensive Income (Loss), Net of Tax	0	0	0	0
Net Income (Loss) Attributable to Parent	(58,805)	(72,272)	(120,824)	(122,065)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(58,805)	(72,272)	(120,824)	(122,065)
Total revenues	(20,533)	(9,726)	(31,982)	(19,527)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	0	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	$ 0	$ 0	$ 0	$ 0