Commitments and Contingencies (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 01, 2012	Jan. 02, 2012
Commitments and Contingencies [Abstract]
Tenant improvement allowance	$ 2,500
Additional tenant improvement allowance	3,000
Amount funded from tenant allowance	4,300
Rent expense	3,200	1,600	1,600
Purchase obligation, minimum amount	7,500
Purchase obligation, minimum payment threshold	2,000
Purchase obligation, percent of shortfall used to calculate remaining obligation	50.00%
Purchase obligation, remaining obligation	6,900
Contingent payment, amount	14,000
License fees	200
Aggregate amount of payments made under license agreement	$ 5,700
Leased facility square footage	53,000			21,000	74,000