Condensed Consolidating Financials Condensed Income Statement (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Total revenues	$ 161,253	$ 134,124
Interest expense (income), net	10,313	4,948
Other expense (income), net	(784)	(319)
Income Tax Expense (Benefit)	9,124	8,191
Cost of revenues	28,186	23,388
Gross Profit	133,067	110,736
Selling and Marketing Expense	37,590	32,959
Research and Development Expense	8,447	7,213
General and Administrative Expense	46,500	28,979
Operating Expenses	92,537	69,151
Income from operations	40,530	41,585
Income (Loss) from Subsidiaries, before Tax	0	0
Income (loss) before income taxes	31,001	36,956
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	21,877	28,765
Net Income (Loss) Attributable to Parent	21,877	28,765
j2 Global, Inc. [Member]
Total revenues	0	0
Interest expense (income), net	2,588	0
Other expense (income), net	(12)	0
Income Tax Expense (Benefit)	(2,381)	0
Cost of revenues	0	0
Gross Profit	0	0
Selling and Marketing Expense	0	0
Research and Development Expense	0	0
General and Administrative Expense	4,179	0
Operating Expenses	4,179	0
Income from operations	(4,179)	0
Income (Loss) from Subsidiaries, before Tax	26,251	0
Income (loss) before income taxes	19,496	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	21,877	0
j2 Cloud Services, Inc. [Member]
Total revenues	54,619	51,193
Interest expense (income), net	5,107	5,103
Other expense (income), net	339	(32)
Income Tax Expense (Benefit)	10,448	3,143
Cost of revenues	15,528	19,953
Gross Profit	39,091	31,240
Selling and Marketing Expense	9,780	9,013
Research and Development Expense	3,855	3,620
General and Administrative Expense	6,850	9,570
Operating Expenses	20,485	22,203
Income from operations	18,606	9,037
Income (Loss) from Subsidiaries, before Tax	23,539	27,942
Income (loss) before income taxes	36,699	31,908
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	26,251	28,765
Non-Guarantor Subsidiaries [Member]
Total revenues	116,435	96,634
Interest expense (income), net	2,618	(155)
Other expense (income), net	(1,111)	(287)
Income Tax Expense (Benefit)	1,057	5,048
Cost of revenues	22,394	17,065
Gross Profit	94,041	79,569
Selling and Marketing Expense	27,875	24,019
Research and Development Expense	4,592	3,593
General and Administrative Expense	35,471	19,409
Operating Expenses	67,938	47,021
Income from operations	26,103	32,548
Income (Loss) from Subsidiaries, before Tax	0	0
Income (loss) before income taxes	24,596	32,990
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	23,539	27,942
Consolidation, Eliminations [Member]
Total revenues	(9,801)	(13,703)
Interest expense (income), net	0	0
Other expense (income), net	0	0
Income Tax Expense (Benefit)	0	0
Cost of revenues	(9,736)	(13,630)
Gross Profit	(65)	(73)
Selling and Marketing Expense	(65)	(73)
Research and Development Expense	0	0
General and Administrative Expense	0	0
Operating Expenses	(65)	(73)
Income from operations	0	0
Income (Loss) from Subsidiaries, before Tax	(49,790)	(27,942)
Income (loss) before income taxes	(49,790)	(27,942)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (49,790)	$ (27,942)