Debt (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended					9 Months Ended	12 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011	Dec. 31, 2011	Sep. 30, 2012 Seven Point Two Five Percent Unsecured Notes Due February One Two Thousand And Nineteen [Member]	Dec. 31, 2011 Seven Point Two Five Percent Unsecured Notes Due February One Two Thousand And Nineteen [Member]	Sep. 30, 2012 Other Indebtedness [Member]	Dec. 31, 2011 Other Indebtedness [Member]
Debt Instrument [Line Items]
Minimum interest rate								0.00%	0.00%
Maximum interest rate								6.00%	6.00%
Debt Instrument, Maturity year, start								2012	2012
Debt Instrument, Maturity year, end								2017	2016
Average borrowings outstanding	$ 456,300,000	$ 417,600,000	$ 467,300,000	$ 406,900,000
Weighted average interest rate of borrowings	7.00%	7.20%	7.00%	7.20%
Net interest expense incurred	8,100,000	7,700,000	24,400,000	21,600,000
Fair value of debt instrument						485,200,000	460,500,000
Carrying value of debt instrument	$ 397,375,000		$ 397,375,000		$ 397,065,000	$ 397,400,000	$ 397,100,000