Condensed Consolidating Financials Condensed Comprehensive Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 29,943	$ 21,877
Foreign currency translation adjustment, net of tax (benefit)	3,415	(15,237)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(2,361)	380
Other Comprehensive Income (Loss), Net of Tax	1,054	(14,857)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	30,997	7,020
Total revenues	200,502	161,253
j2 Global, Inc. [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	29,943	21,877
Foreign currency translation adjustment, net of tax (benefit)	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(2,361)	311
Other Comprehensive Income (Loss), Net of Tax	(2,361)	311
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	27,582	22,188
Total revenues	0	0
j2 Cloud Services, Inc. [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	34,323	26,251
Foreign currency translation adjustment, net of tax (benefit)	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	69
Other Comprehensive Income (Loss), Net of Tax	0	69
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	34,323	26,320
Total revenues	56,385	54,619
Non-Guarantor Subsidiaries [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	27,696	23,539
Foreign currency translation adjustment, net of tax (benefit)	3,415	(15,237)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	0
Other Comprehensive Income (Loss), Net of Tax	3,415	(15,237)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	31,111	8,302
Total revenues	155,566	116,435
Consolidation, Eliminations [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(62,019)	(49,790)
Foreign currency translation adjustment, net of tax (benefit)	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	0
Other Comprehensive Income (Loss), Net of Tax	0	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(62,019)	(49,790)
Total revenues	$ (11,449)	$ (9,801)