Agreement with SK hynix (Details 4) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended
	Dec. 31, 2013 SK hynix	Jun. 11, 2013 SK hynix	Dec. 31, 2013 SK hynix Royalty revenue	Jun. 11, 2013 SK hynix Royalty revenue	Dec. 31, 2013 SK hynix Gain from settlement	Dec. 31, 2013 Micron	Dec. 09, 2013 Micron	Dec. 31, 2013 Micron Royalty revenue	Dec. 09, 2013 Micron Royalty revenue	Dec. 31, 2013 Micron Gain from settlement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cash Received to date in 2013	$ 24.0		$ 23.6		$ 0.4	$ 5.5		$ 5.3		$ 0.2
Estimated to Be Received in 2014	48.0		47.3		0.7	40.0		38.7		1.3
Estimated to Be Received in 2015	48.0		47.3		0.7	40.0		38.7		1.3
Estimated to Be Received in 2016	48.0		47.9		0.1	40.0		39.5		0.5
Estimated to Be Received in 2017	48.0		48.0		0	40.0		40.0		0
Estimated to Be Received in 2018	24.0		24.0		0	114.5		114.5		0
Total Estimated Cash receipts	$ 240.0	$ 240.0	$ 238.1	$ 238.1	$ 1.9	$ 280.0	$ 280.0	$ 276.7	$ 276.7	$ 3.3