Derivative Instruments And Hedging Activities , Derivative Contracts (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 01, 2012
Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of Interest Rate Derivatives Held (number of derivative contracts)	4
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of Interest Rate Derivatives Held (number of derivative contracts)	2
Notional Amount of Derivatives	45.0
Interest Rate Swap [Member] | Derivative Maturing 2012 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	25.0
Derivative, Type	Swap
Derivative, Purpose	Floating to Fixed Rate
Derivative, Effective Date	Sep. 01, 2002
Derivative, Maturity Date	Jul. 01, 2012
Derivative, Based on	3 Month LIBOR
Derivative, Variable Rate	0.581%
Derivative, Fixed Rate	4.70%
Derivative, Spread on Variable Rate	1.87%
Derivative, Effective Fixed Rate	6.57%
Interest Rate Swap [Member] | Derivative Maturing 2014 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	20.0
Derivative, Type	Swap
Derivative, Purpose	Floating to Fixed Rate
Derivative, Effective Date	Jan. 01, 2009
Derivative, Maturity Date	Jan. 01, 2014
Derivative, Based on	3 Month LIBOR
Derivative, Variable Rate	0.581%
Derivative, Fixed Rate	2.145%
Derivative, Spread on Variable Rate	1.87%
Derivative, Effective Fixed Rate	4.015%
Interest Rate Cap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of Interest Rate Derivatives Held (number of derivative contracts)	2
Notional Amount of Derivatives	162.4
Interest Rate Cap [Member] | Derivative Maturing 2015 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	152.4
Derivative, Type	Cap
Derivative, Purpose	Cap Floating Rate
Derivative, Effective Date	Apr. 28, 2009
Derivative, Maturity Date	May 01, 2012
Derivative, Based on	3 Month LIBOR
Derivative, Variable Rate	0.468%
Derivative, Fixed Rate	11.00%
Derivative, Spread on Variable Rate	0.00%
Interest Rate Cap [Member] | Derivative Maturing 2016 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	10.0
Derivative, Type	Cap
Derivative, Purpose	Cap Floating Rate
Derivative, Effective Date	Oct. 03, 2011
Derivative, Maturity Date	Oct. 03, 2016
Derivative, Based on	3 Month LIBOR
Derivative, Variable Rate	0.468%
Derivative, Fixed Rate	11.02%
Derivative, Spread on Variable Rate	0.00%
New interest rate cap agreement [Member] | Interest Rate Cap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives		$ 152.4
Derivative, Effective Date	Apr. 01, 2012
Derivative, Maturity Date	Apr. 01, 2015
Derivative, Based on	90-Day LIBOR
Derivative, Fixed Rate		11.265%