Long Term Debt (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Jul. 26, 2012	Jun. 10, 2014
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 653,000,000			$ 653,000,000
Debt Instrument, Unamortized Discount					5,000,000
Interest Expense	32,500,000	22,300,000	9,000,000
Long-term Debt	593,350,000	245,670,000		593,350,000
Long-term Debt, Current Maturities	0			0
Total long-term debt, less current portion	593,350,000			593,350,000
Long-term Debt, Fair Value	711,100,000	283,300,000		711,100,000
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Issuance Date	Jul. 26, 2012
Debt Instrument, Face Amount	250,000,000			250,000,000
Debt Instrument, Interest Rate, Stated Percentage	8.00%			8.00%
Debt Instrument, Maturity Date	Aug. 01, 2020
Proceeds from Debt, Net of Issuance Costs	245,000,000
Debt Instrument, Unamortized Discount	3,800,000			3,800,000
Unamortized Debt Issuance Expense	1,100,000			1,100,000
Debt Instrument, Frequency of Periodic Payment				semi-annually
Debt Instrument, Call Date, Earliest	Aug. 01, 2016
Debt Instrument, Covenant Description	The indenture governing the Senior Notes contain certain restrictive and other covenants applicable to j2 Cloud Services, Inc. and subsidiaries designated as restricted subsidiaries including, but not limited to, limitations on debt and disqualified or preferred stock, restricted payments, liens, sale and leaseback transactions, dividends and other payment restrictions, asset sales and transactions with affiliates.
Long-term Debt	246,187,000			246,187,000
Long-term Debt, Fair Value	262,400,000			262,400,000
Convertible Debt Securities [Member]
Debt Instrument [Line Items]
Debt Instrument, Issuance Date	Jun. 10, 2014
Debt Instrument, Face Amount	403,000,000			403,000,000
Debt Instrument, Interest Rate, Stated Percentage	3.25%			3.25%
Debt Instrument, Maturity Date	Jun. 15, 2029
Proceeds from Debt, Net of Issuance Costs	391,000,000
Debt Instrument, Unamortized Discount	55,300,000			55,300,000		59,000,000
Debt Instrument, Convertible, Remaining Discount Amortization Period	6 years 6 months
Debt Issuance Cost	11,700,000
Unamortized Debt Issuance Expense	9,300,000			9,300,000
Debt Instrument, Frequency of Periodic Payment				semiannually
Debt Instrument, Convertible, Carrying Amount of Equity Component						37,700,000
Long-term Debt	347,200,000			347,200,000
Long-term Debt, Fair Value	448,700,000			448,700,000
Interest Expense, Debt	$ 11,700,000