Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ (56,558)	$ 56,089	$ 117,016
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation of property and equipment	7,201	2,260	1,590
Amortization of intangible assets	111,930	31,870	20,624
Stock-based compensation expense	33,462	21,101	11,517
Bad debt expense	2,404	0	0
Deferred income tax and other, net	(18,294)	7,694	19,477
Amortization of premium or discount on investments	372	4,072	(2,601)
Patents acquired through settlement agreements	(1,664)	0	0
Loss on disposal of property and equipment	251	0	0
Amortization of debt issuance costs	2,423	201	0
Changes in operating assets and liabilities, net of business acquisitions:
Accounts receivable	(3,551)	13,957	2,694
Unbilled contract receivable, net	48,168	0	0
Other assets	3,458	18,067	(10,051)
Accounts payable	(3,298)	1,709	(2,685)
Accrued legal fees	(22)	4,884	(1,819)
Accrued and other liabilities	19,192	(1,573)	(5,074)
Deferred revenue	1,791	(6,471)	(3,412)
Net cash from operating activities	147,265	153,860	147,276
Cash flows from investing activities:
Purchases of property and equipment	(3,323)	(3,794)	(1,002)
Proceeds from sale of property and equipment	235	0	0
Purchases of short-term available-for-sale investments	(33,102)	(161,595)	(298,848)
Proceeds from sales of short-term investments	1,035	299,524	149,975
Proceeds from maturities of short-term investments	16,487	171,255	174,738
Acquisition, net of cash acquired	0	(888,204)	(38,561)
Purchases of intangible assets	(176)	(9,582)	(7,588)
Net cash from investing activities	(18,844)	(592,396)	(21,286)
Cash flows from financing activities:
Proceeds from debt, net	0	583,039	0
Repayment of debt	(6,000)	0	0
Dividend paid	(39,509)	(39,158)	(41,677)
Proceeds from exercise of stock options	4,873	6,285	8,995
Proceeds from employee stock purchase program	4,132	1,998	1,665
Repurchase of common stock	(19,283)	(70,601)	(123,282)
Net cash from financing activities	(55,787)	481,563	(154,299)
Net increase (decrease) in cash and cash equivalents	72,634	43,027	(28,309)
Cash and cash equivalents at beginning of period	65,626	22,599	50,908
Cash and cash equivalents at end of period	138,260	65,626	22,599
Supplemental disclosure of cash flow information:
Interest paid	28,068	0	0
Income taxes paid, net of refunds	15,678	7,676	36,781
Supplemental disclosure of non-cash investing activities:
Fair value of unvested DTS equity awards assumed relating to pre-acquisition services	$ 0	$ 13,124	$ 0