Intangible and Other Assets, Net (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011 Year	Dec. 31, 2010 Year	Dec. 31, 2009 Year
Finite-Lived Intangible Assets [Line Items]
Finite lived intangible assets, amortization expense	$ 1,700,000	$ 900,000	$ 1,000,000
Finite lived intangible assets, Weighted average amortization period	14.9	14.8	15.2
Finite lived intangible assets, estimated future amortization expense year one	470,000
Finite lived intangible assets, estimated future amortization expense year two	435,000
Finite lived intangible assets, estimated future amortization expense year three	435,000
Finite lived intangible assets, estimated future amortization expense year four	435,000
Finite lived intangible assets, estimated future amortization expense year five	435,000
Finite lived intangible assets, estimated future amortization expense after year five	3,500,000
Capitalized patent and license costs [Member]
Finite-Lived Intangible Assets [Line Items]
Research and development expense	$ 312,000	$ 2,400,000	$ 47,000