Discontinued Operations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 27, 2012	Dec. 31, 2012	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale of ownership interests, Disposal Group	$ 227.5
Percentage of ownership in TCAE by TPS GO	96.06%
Foreign tax credits		22.9	24.9
TPS GO [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale of ownership interests, Disposal Group	12.5
TPS SJI [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale of ownership interests, Disposal Group	213.5
TGS [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale of ownership interests, Disposal Group	$ 1.5