Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income including noncontrolling interests in operating subsidiaries	$ 59,289	$ 21,645	$ 37,016
Adjustments to reconcile net income including noncontrolling interests in operating subsidiaries to net cash provided by operating activities:
Depreciation and amortization	39,168	9,850	7,017
Non-cash stock compensation	25,657	13,579	7,121
Change in valuation allowance	(10,651)	0	0
Other	777	(15)	(32)
Changes in assets and liabilities:
Accounts receivable	(6,928)	5,072	(2,877)
Prepaid expenses and other assets	(1,294)	1,075	(757)
Accounts payable and accrued expenses / costs	3,039	(1,364)	(1,414)
Royalties and contingent legal fees payable	(11,000)	10,748	358
Deferred revenues	0	0	(1,510)
Deferred income tax	6,546	0	0
Net cash provided by operating activities	104,603	60,590	44,922
Cash flows from investing activities:
Purchase of property and equipment	(268)	(190)	(58)
Purchase of available-for-sale investments	(402,500)	(8,427)	0
Sale of available-for-sale investments	322,236	60	184
Purchase of ADAPTIX, Inc., net of cash acquired	(150,000)	0	0
Patent acquisition costs	(178,260)	(14,680)	(8,224)
Net cash used in investing activities	(408,792)	(23,237)	(8,098)
Cash flows from financing activities:
Proceeds from sale of common stock, net of issuance costs	218,961	175,229	0
Repurchases of common stock	(26,732)	0	0
Distributions to noncontrolling interests in operating subsidiary	(312)	(2,897)	(4,807)
Contributions from noncontrolling interests in operating subsidiary, net of issuance costs	5,793	1,539	2,393
Proceeds from the exercise of stock options	340	411	15,068
Excess tax benefits from stock-based compensation	13,210	583	1,302
Net cash provided by financing activities	211,260	174,865	13,956
Increase in cash and cash equivalents	(92,929)	212,218	50,780
Cash and cash equivalents, beginning	314,733	102,515	51,735
Cash and cash equivalents, ending	$ 221,804	$ 314,733	$ 102,515