Condensed Consolidating Financials Condensed Comprehensive Income Statement (Details) - Scenario, Unspecified [Domain] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 38,916	$ 35,049	$ 60,794	$ 63,814
Foreign currency translation adjustment, net of tax (benefit)	7,112	1,334	(8,125)	2,171
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(3,934)	2,885	(3,554)	245
Other Comprehensive Income (Loss), Net of Tax	3,178	4,219	(11,679)	2,416
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	42,094	39,268	49,115	66,230
Total revenues	176,038	144,744	337,291	278,868
j2 Global, Inc. [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	38,916	(671)	60,794	(671)
Foreign currency translation adjustment, net of tax (benefit)	0	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(267)	0	44	0
Other Comprehensive Income (Loss), Net of Tax	(267)	0	44	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	38,649	(671)	60,838	(671)
Total revenues	0	0	0	0
j2 Cloud Services, Inc. [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	45,530	35,720	71,782	64,485
Foreign currency translation adjustment, net of tax (benefit)	0	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(3,667)	2,477	(3,598)	(421)
Other Comprehensive Income (Loss), Net of Tax	(3,667)	2,477	(3,598)	(421)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	41,863	38,197	68,184	64,064
Total revenues	56,547	65,313	111,166	116,507
Non-Guarantor Subsidiaries [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	26,742	12,780	50,283	40,720
Foreign currency translation adjustment, net of tax (benefit)	7,112	1,334	(8,125)	2,171
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	408	0	666
Other Comprehensive Income (Loss), Net of Tax	7,112	1,742	(8,125)	2,837
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	33,854	14,522	42,158	43,557
Total revenues	129,217	106,042	245,652	202,676
Consolidation, Eliminations [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(72,272)	(12,780)	(122,065)	(40,720)
Foreign currency translation adjustment, net of tax (benefit)	0	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	0	0	0
Other Comprehensive Income (Loss), Net of Tax	0	0	0	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(72,272)	(12,780)	(122,065)	(40,720)
Total revenues	$ (9,726)	$ (26,611)	$ (19,527)	$ (40,315)