Goodwill and Acquired Intangible Assets, Net (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2013 Epay Segment [Member]
Goodwill and Finite-lived Intangible Assets Rollforward [Roll Forward]
Finite-Lived Intangible Assets, Net	$ 170,184,000	$ 93,026,000
Finite-lived intangible assets acquired during period	102,841,000
Finite-Lived Intangible Assets, Amortization Expense	(17,661,000)
Finite-lived intangible assets, other changes	(8,022,000)
Goodwill	619,285,000	498,435,000
Goodwill, Acquired During Period	156,748,000
Goodwill, Other Changes	(35,898,000)
Intangible Assets, Net (Including Goodwill)	789,469,000	591,461,000
Total intangible assets acquired during period	259,589,000
Total intangible assets amortization expense	(17,661,000)
Total intangible assets, other changes	(43,920,000)
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	6,900,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	22,700,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	21,100,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	18,900,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	16,500,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	15,700,000
Goodwill, Impairment Loss			$ 18,400,000