Business Combinations (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 02, 2015 Companies	Dec. 02, 2014	Nov. 03, 2014	May 21, 2014	Jan. 27, 2014	Dec. 31, 2014	Dec. 31, 2013	Mar. 01, 2015	Dec. 01, 2014
Business Acquisition [Line Items]
Document Period End Date	Mar. 31, 2015
Reduction of acquisition earnout accruals	$ 0	$ (1,762)
Derivative Liability	5,330							5,367	14,420
Business acquisition, contingent consideration, at fair value, noncurrent	4,443							4,480
Business acquisition, contingent consideration, at fair value, current	887							887
Goodwill	399,408							402,220	337,068
Via Media Health [Member]
Business Acquisition [Line Items]
Number of businesses acquired			1
Purchase Price of Business Acquisition, Cost of Acquired Entity										1,000
Derivative, Term of Contract			24 months 0 days
Oakstone [Member]
Business Acquisition [Line Items]
Payments to Acquire Business, Net				23,720
Payments to Acquire Businesses, Gross				31,370
Net working capital adjustment				7,650
Goodwill				28,769
Deferred Revenue				6,500
Oakstone [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)				1,691
Oakstone [Member] | Developed technology [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)				501
i3 [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross				2,000
Goodwill											3,700
i3 [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)											225
i3 [Member] | Developed technology [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)											75
Vertex [Member]
Business Acquisition [Line Items]
Derivative, Term of Contract					24 months
Payments to Acquire Businesses, Gross					27,250
Goodwill					27,728
Vertex [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)					2,502
Vertex [Member] | Developed technology [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)					235
Healthcare Magic [Member]
Business Acquisition [Line Items]
Derivative Liability	596
Derivative, Term of Contract						24 months
Payments to Acquire Businesses, Gross						6,000
Goodwill						5,619
Healthcare Magic [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)						452
Healthcare Magic [Member] | Developed technology [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)						100
Healthcare Magic [Member] | Trademarks and Trade Names [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)						59
Healthcare Magic [Member] | Non-compete agreements [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)						226
Curepet, Inc. [Member]
Business Acquisition [Line Items]
Purchase Price of Business Acquisition, Cost of Acquired Entity							6,350
Derivative Liability	0						5,000
Purchase Price of Business acquisition, Non-Cash portion of Acquired Entity							1,350
Derivative, Term of Contract							36 months 0 days
Contingent Accrued Earn-out Acquisition Consideration [Member]
Business Acquisition [Line Items]
Derivative Liability	5,330							5,367
Business acquisition, contingent consideration, at fair value, noncurrent	4,400							4,500
Business acquisition, contingent consideration, at fair value, current	900							900
Maximum [Member] | Via Media Health [Member]
Business Acquisition [Line Items]
Derivative Liability										372
Maximum [Member] | i3 [Member]
Business Acquisition [Line Items]
Derivative Liability											4,000
Maximum [Member] | Vertex [Member]
Business Acquisition [Line Items]
Derivative Liability											2,000
Maximum [Member] | Healthcare Magic [Member]
Business Acquisition [Line Items]
Derivative Liability						12,360
Maximum [Member] | Curepet, Inc. [Member]
Business Acquisition [Line Items]
Derivative Liability							$ 5,000