Condensed Consolidating Financials Condensed Comprehensive Income Statement (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Other Comprehensive (Income) Loss, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	$ 0	$ (15)	$ 0	$ (22)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	35,049	35,967	63,814	58,738
Net Income (Loss) Attributable to Noncontrolling Interest	0	(73)	0	(224)
Foreign currency translation adjustment, net of tax (benefit)	1,334	(363)	2,171	(2,116)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	2,885	2,180	245	5,001
Other Comprehensive Income (Loss), Net of Tax	4,219	1,817	2,416	2,885
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	39,268	37,784	66,230	61,623
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	39,268	37,872	66,230	61,869
j2 Global, Inc. [Member]
Other Comprehensive (Income) Loss, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest		0		0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(671)	0	(671)	0
Net Income (Loss) Attributable to Noncontrolling Interest		0		0
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		0		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(671)	0	(671)	0
j2 Cloud Services, Inc. [Member]
Other Comprehensive (Income) Loss, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest		0		0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	22,940	15,693	23,765	22,372
Net Income (Loss) Attributable to Noncontrolling Interest		0		0
Foreign currency translation adjustment, net of tax (benefit)	0	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	2,477	2,355	(421)	5,767
Other Comprehensive Income (Loss), Net of Tax	2,477	2,355	(421)	5,767
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		18,048		28,139
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	25,417	18,048	23,344	28,139
Non-Guarantor Subsidiaries [Member]
Other Comprehensive (Income) Loss, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest		(15)		(22)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	12,780	20,274	40,720	36,366
Net Income (Loss) Attributable to Noncontrolling Interest		0		0
Foreign currency translation adjustment, net of tax (benefit)	1,334	(363)	2,171	(2,116)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	408	(175)	666	(766)
Other Comprehensive Income (Loss), Net of Tax	1,742	(538)	2,837	(2,882)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		19,736		33,484
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	14,522	19,751	43,557	33,506
Consolidation, Eliminations [Member]
Other Comprehensive (Income) Loss, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest		0		0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	0	0	0	0
Net Income (Loss) Attributable to Noncontrolling Interest		(73)		(224)
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		0		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 0	$ 73	$ 0	$ 224