Goodwill and Acquired Intangible Assets - Schedule of Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 399,191	$ 402,801
Accumulated amortization	(230,843)	(201,542)
Net carrying amount	168,348	201,259
Completed technologies
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	145,091	145,091
Accumulated amortization	(81,587)	(65,283)
Net carrying amount	63,504	79,808
Customer-related intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	245,710	245,310
Accumulated amortization	(144,786)	(128,835)
Net carrying amount	100,924	116,475
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	700	4,710
Accumulated amortization	(306)	(3,975)
Net carrying amount	394	735
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	7,200	7,200
Accumulated amortization	(3,674)	(2,959)
Net carrying amount	3,526	4,241
Acquired license rights
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	490	490
Accumulated amortization	(490)	(490)
Net carrying amount	$ 0	$ 0