Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended				0 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2011 Maximum [Member] LIBOR [Member]	Dec. 31, 2011 Minimum [Member] LIBOR [Member]	Dec. 31, 2011 Spread In Effect At Closing [Member] LIBOR [Member]	Aug. 14, 2008 Revolving Credit Agreement [Member]	Dec. 31, 2011 Letter Of Credit [Member]
Loss Contingencies [Line Items]
Operating lease term range, minimum years	1
Operating lease term range, maximum years	17
Contingent liability of Zebra						$ 1,468,000
Revolving credit agreement in years					5
Revolving credit agreement amount					$ 100,000,000	$ 3,500,000
Debt instrument spread interest rate		1.25%	0.50%	0.50%