Acquisitions Acquisition (Purchase Price Allocation) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 08, 2019	Aug. 23, 2019	Dec. 31, 2018
Business Acquisition
Goodwill	$ 183,222	$ 183,465			$ 207,178
Northwest Logic
Business Acquisition
Cash and cash equivalents				$ 159
Accounts receivable				1,679
Prepaid expenses and other current assets				65
Operating lease right-of-use assets				178
Identified intangible assets				8,800
Goodwill				13,477
Other asset				9
Accounts payable				(9)
Operating lease liability				(178)
Other current liabilities				(108)
Deferred tax liability, net				(2,133)
Recognized identifiable assets acquired and liabilities assumed, net				$ 21,939
Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition
Prepaid expenses and other current assets			$ 267
Unbilled receivables			6,765
Operating lease right-of-use assets			852
Identified intangible assets			23,500
Goodwill			16,845
Deferred revenue			(310)
Operating lease liability			(852)
Other current liabilities			(267)
Recognized identifiable assets acquired and liabilities assumed, net			$ 46,800