Condensed Consolidating Financials Condensed Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$ 272,368		$ 433,663	$ 514,997	$ 207,801
Short-term investments	85,410		96,206
Accounts receivable, net of allowances of $4,094 and $3,685, respectively	97,376		91,699
Prepaid expenses and other current assets	36,738		22,602
Deferred income taxes	7,787		2,013
Due from Affiliate, Current	0		0
Total current assets	499,679		646,183
Long-term investments	52,889		60,508
Property and equipment, net	59,829		38,217
Tradenames, net	123,338		105,551
Patent and patent licenses, net	20,352		24,927
Customer Relationships, Net	205,760		163,766
Goodwill	772,916		635,675
Other purchased intangibles, net	16,637		17,556
Investments in and Advances to Affiliates, Amount of Equity	0		0
Other assets	13,599		12,819
Total assets	1,764,999		1,705,202
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	89,638		95,310
Income taxes payable	62		0
Deferred revenue, current	75,117		63,457
Capital Lease Obligations, Current	248		258
Deferred Tax Liabilities, Net, Current	364		342
Due to Affiliate, Current	0		0
Total current liabilities	165,429		159,367
Long-term Debt	599,183		593,350
Capital Lease Obligations, Noncurrent	175		141
Liability for uncertain tax positions	27,634		37,551
Deferred income taxes	66,206		61,960
Deferred revenue, non-current	7,367		10,182
Other long-term liabilities	27,039		22,416
Total liabilities	$ 893,033		$ 884,967
Commitments and contingencies
Common Stock, Value, Issued	$ 477		$ 474
Additional paid-in capital	289,196		273,304
Retained Earnings (Accumulated Deficit)	606,808		553,584
Accumulated Other Comprehensive Income (Loss), Net of Tax	(24,515)	$ (18,806)	(7,127)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	871,966		820,235
Total liabilities and stockholders’ equity	1,764,999		1,705,202
Series A Preferred Stock [Member]
LIABILITIES AND STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value	0		0
Series B Preferred Stock [Member]
LIABILITIES AND STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value	0		0
j2 Global, Inc. [Member]
ASSETS
Cash and cash equivalents	109,554		226,790	313,667	0
Short-term investments	85,353		47,880
Accounts receivable, net of allowances of $4,094 and $3,685, respectively	69		0
Prepaid expenses and other current assets	10,289		776
Deferred income taxes	267		1,271
Due from Affiliate, Current	92,000		110,000
Total current assets	297,532		386,717
Long-term investments	52,889		55,452
Property and equipment, net	0		0
Tradenames, net	0		0
Patent and patent licenses, net	0		0
Customer Relationships, Net	0		0
Goodwill	0		0
Other purchased intangibles, net	0		0
Investments in and Advances to Affiliates, Amount of Equity	1,027,107		826,289
Other assets	8,506		9,328
Total assets	1,386,034		1,277,786
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	7,102		2,834
Income taxes payable	0		0
Deferred revenue, current	0		0
Capital Lease Obligations, Current	0		0
Deferred Tax Liabilities, Net, Current	0		0
Due to Affiliate, Current	118,263		76,366
Total current liabilities	125,365		79,200
Long-term Debt	352,579		347,163
Capital Lease Obligations, Noncurrent	0		0
Liability for uncertain tax positions	0		0
Deferred income taxes	26,339		21,728
Deferred revenue, non-current	0		0
Other long-term liabilities	1,071		744
Total liabilities	505,354		448,835
Common Stock, Value, Issued	477		474
Additional paid-in capital	289,196		273,304
Retained Earnings (Accumulated Deficit)	600,139		555,158
Accumulated Other Comprehensive Income (Loss), Net of Tax	(9,132)		15
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	880,680		828,951
Total liabilities and stockholders’ equity	1,386,034		1,277,786
j2 Cloud Services, Inc. [Member]
ASSETS
Cash and cash equivalents	11,854		36,810	14,799	34,406
Short-term investments	0		48,261
Accounts receivable, net of allowances of $4,094 and $3,685, respectively	11,353		11,167
Prepaid expenses and other current assets	18,486		12,689
Deferred income taxes	857		0
Due from Affiliate, Current	153,610		74,938
Total current assets	196,160		183,865
Long-term investments	0		5,056
Property and equipment, net	7,064		8,011
Tradenames, net	10,145		10,231
Patent and patent licenses, net	779		886
Customer Relationships, Net	1,445		2,206
Goodwill	53,543		52,131
Other purchased intangibles, net	4,232		4,276
Investments in and Advances to Affiliates, Amount of Equity	1,081,389		900,681
Other assets	2,928		1,368
Total assets	1,357,685		1,168,711
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	25,860		28,414
Income taxes payable	4,430		0
Deferred revenue, current	19,847		23,091
Capital Lease Obligations, Current	0		0
Deferred Tax Liabilities, Net, Current	0		0
Due to Affiliate, Current	0		0
Total current liabilities	50,137		51,505
Long-term Debt	246,604		246,187
Capital Lease Obligations, Noncurrent	0		0
Liability for uncertain tax positions	27,634		37,551
Deferred income taxes	0		(1,837)
Deferred revenue, non-current	5,446		8,187
Other long-term liabilities	757		829
Total liabilities	330,578		342,422
Common Stock, Value, Issued	0		0
Additional paid-in capital	236,965		232,340
Retained Earnings (Accumulated Deficit)	785,386		584,591
Accumulated Other Comprehensive Income (Loss), Net of Tax	4,756		9,358
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,027,107		826,289
Total liabilities and stockholders’ equity	1,357,685		1,168,711
Non-Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	150,960		170,063	186,531	173,395
Short-term investments	57		65
Accounts receivable, net of allowances of $4,094 and $3,685, respectively	85,954		80,532
Prepaid expenses and other current assets	12,331		9,137
Deferred income taxes	6,663		742
Due from Affiliate, Current	0		1,428
Total current assets	255,965		261,967
Long-term investments	0		0
Property and equipment, net	52,765		30,206
Tradenames, net	113,193		95,320
Patent and patent licenses, net	19,573		24,041
Customer Relationships, Net	204,315		161,560
Goodwill	719,373		583,544
Other purchased intangibles, net	12,405		13,280
Investments in and Advances to Affiliates, Amount of Equity	8,714		8,716
Other assets	2,165		2,123
Total assets	1,388,468		1,180,757
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	56,676		64,062
Income taxes payable	0		0
Deferred revenue, current	55,270		40,366
Capital Lease Obligations, Current	248		258
Deferred Tax Liabilities, Net, Current	364		342
Due to Affiliate, Current	127,347		110,000
Total current liabilities	239,905		215,028
Long-term Debt	0		0
Capital Lease Obligations, Noncurrent	175		141
Liability for uncertain tax positions	0		0
Deferred income taxes	39,867		42,069
Deferred revenue, non-current	1,921		1,995
Other long-term liabilities	25,211		20,843
Total liabilities	307,079		280,076
Common Stock, Value, Issued	0		0
Additional paid-in capital	523,584		421,676
Retained Earnings (Accumulated Deficit)	587,147		495,505
Accumulated Other Comprehensive Income (Loss), Net of Tax	(29,342)		(16,500)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,081,389		900,681
Total liabilities and stockholders’ equity	1,388,468		1,180,757
Consolidation, Eliminations [Member]
ASSETS
Cash and cash equivalents	0		0	$ 0	$ 0
Short-term investments	0		0
Accounts receivable, net of allowances of $4,094 and $3,685, respectively	0		0
Prepaid expenses and other current assets	(4,368)		0
Deferred income taxes	0		0
Due from Affiliate, Current	(245,610)		(186,366)
Total current assets	(249,978)		(186,366)
Long-term investments	0		0
Property and equipment, net	0		0
Tradenames, net	0		0
Patent and patent licenses, net	0		0
Customer Relationships, Net	0		0
Goodwill	0		0
Other purchased intangibles, net	0		0
Investments in and Advances to Affiliates, Amount of Equity	(2,117,210)		(1,735,686)
Other assets	0		0
Total assets	(2,367,188)		(1,922,052)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	0		0
Income taxes payable	(4,368)		0
Deferred revenue, current	0		0
Capital Lease Obligations, Current	0		0
Deferred Tax Liabilities, Net, Current	0		0
Due to Affiliate, Current	(245,610)		(186,366)
Total current liabilities	(249,978)		(186,366)
Long-term Debt	0		0
Capital Lease Obligations, Noncurrent	0		0
Liability for uncertain tax positions	0		0
Deferred income taxes	0		0
Deferred revenue, non-current	0		0
Other long-term liabilities	0		0
Total liabilities	(249,978)		(186,366)
Common Stock, Value, Issued	0		0
Additional paid-in capital	(760,549)		(654,016)
Retained Earnings (Accumulated Deficit)	(1,365,864)		(1,081,670)
Accumulated Other Comprehensive Income (Loss), Net of Tax	9,203		0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(2,117,210)		(1,735,686)
Total liabilities and stockholders’ equity	$ (2,367,188)		$ (1,922,052)