Quarterly Results (Tables)

12 Months Ended

Dec. 31, 2012

Quarterly Results [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

	Year Ended December 31, 2012
	Fourth Quarter		Third Quarter		Second Quarter		First Quarter
Revenues	$	102,033	$	93,246	$	89,465	$	86,652
Gross profit		83,375		76,943		73,278		70,788
Net income attributable to j2 Global, Inc. common shareholders		30,203		31,650		31,188		28,539
Net income per common share:
Basic	$	0.66	$	0.69	$	0.68	$	0.61
Diluted	$	0.65	$	0.69	$	0.67	$	0.60
Weighted average shares outstanding
Basic		45,071,204		45,002,565		45,373,930		46,400,441
Diluted		45,423,502		45,340,111		45,569,564		46,794,603
	Year Ended December 31, 2011
	Fourth Quarter		Third Quarter		Second Quarter		First Quarter
Revenues	$	85,072	$	86,027	$	85,676	$	73,384
Gross profit		70,411		71,025		70,518		57,592
Net income attributable to j2 Global, Inc. common shareholders		29,819		25,498		28,514		30,935
Net income per common share:
Basic	$	0.63	$	0.55	$	0.63	$	0.69
Diluted	$	0.62	$	0.54	$	0.61	$	0.66
Weighted average shares outstanding
Basic		46,692,364		45,993,328		45,399,940		45,093,127
Diluted		46,989,376		46,455,584		46,723,792		46,558,543