Business Combinations - Narrative (Details) - USD ($)		3 Months Ended		9 Months Ended
	May. 09, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition [Line Items]
Changes in carrying amount of goodwill				$ 0
Amortization of intangible assets		$ 11,800,000	$ 11,500,000	35,300,000	$ 33,500,000
nPulse Technologies [Member]
Business Acquisition [Line Items]
Total purchase consideration	$ 56,600,000
Purchase consideration, cash paid	55,200,000
Purchase consideration, fair value of common stock	$ 1,300,000
Performance milestone determination period	3 years 6 months
Goodwill deductible for U.S. federal income tax purposes		$ 0		$ 0
nPulse Technologies [Member] | General and administrative [Member]
Business Acquisition [Line Items]
Acquisition costs	$ 500,000
nPulse Technologies [Member] | Maximum [Member]
Business Acquisition [Line Items]
Purchase consideration, shares issued for acquisition (shares)	54,319
nPulse Technologies [Member] | Unvested stock options and restricted stock [Member]
Business Acquisition [Line Items]
Purchase consideration, equity awards assumed	$ 100,000