Summary of Open Tax Years by Major Jurisdiction (Detail)	12 Months Ended
	Dec. 31, 2011
United States
Income Tax Examination [Line Items]
Open Tax Years	9/2005 - 3/2/2007, 2008 - 2011
California
Income Tax Examination [Line Items]
Open Tax Years	3/2/2007, 2007 - 2011
Connecticut
Income Tax Examination [Line Items]
Open Tax Years	2008 - 2011
Illinois
Income Tax Examination [Line Items]
Open Tax Years	2008 - 2011
Kansas
Income Tax Examination [Line Items]
Open Tax Years	2008 - 2011
Massachusetts
Income Tax Examination [Line Items]
Open Tax Years	2008 - 2011
Michigan
Income Tax Examination [Line Items]
Open Tax Years	2008 - 2011
North Carolina
Income Tax Examination [Line Items]
Open Tax Years	2008 - 2011
Pennsylvania
Income Tax Examination [Line Items]
Open Tax Years	2007 - 2011
Texas
Income Tax Examination [Line Items]
Open Tax Years	3/2/2007, 2007 - 2011