Acquisitions Acquisition (Purchase Price Allocation) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 08, 2019	Sep. 30, 2019	Aug. 23, 2019	Dec. 31, 2018
Business Acquisition
Goodwill	$ 183,222	$ 183,222	$ 183,222	$ 183,465	$ 183,465		$ 164,488		$ 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