Consolidated Statements of Changes in Equity (USD $) In Millions	Total USD ($)	Common Stock [Member] USD ($)	Additional Paid-in Capital [Member] USD ($)	Retained Earnings [Member] USD ($)	Accumulated Other Comprehensive Income [Member] USD ($)	Noncontrolling Interest [Member] USD ($)	Capital Units [Member]
Balance at Dec. 31, 2010	$ 1,138.3	$ 0.9	$ 541.9	$ 603.8	$ (8.4)	$ 0.1
Balance (in shares) at Dec. 31, 2010							86.4
Comprehensive income	29.7	0	0	30.8	(1.5)	0.4
Issuance of restricted stock to employees, net of forfeitures (in shares)							1.7
Amortization of restricted stock	11.1	0	11.1	0	0	0
Distributions to noncontrolling interest	(0.3)	0	0	0	0	(0.3)
Tax effects from vesting of restricted stock	0.9	0	0.9	0	0	0
Tax effects of expired employee stock options	(1.2)	0	(1.2)	0	0	0
Repurchase of common shares	(28.0)	0	(13.3)	(14.7)	0	0
Repurchase of common shares (in shares)							(2.2)
Dividends on common stock ($0.10 per share)	(8.7)	0	0	(8.7)	0	0
Other	0.1	0	0	0.1	0	0
Balance at Jul. 02, 2011	1,141.9	0.9	539.4	611.3	(9.9)	0.2
Balance (in shares) at Jul. 02, 2011							85.9
Balance at Dec. 31, 2011	1,089.4	0.8	521.8	596.2	(29.6)	0.2
Balance (in shares) at Dec. 31, 2011							81.0
Comprehensive income	8.7	0	0	6.9	1.3	0.5
Issuance of restricted stock to employees, net of forfeitures (in shares)							2.2
Amortization of restricted stock	13.3	0	13.3	0	0	0
Distributions to noncontrolling interest	(0.4)	0	0	0	0	(0.4)
Tax effects from vesting of restricted stock	1.5	0	1.5	0	0	0
Tax effects of expired employee stock options	(1.5)	0	(1.5)	0	0	0
Repurchase of common shares	(29.2)	0	(13.8)	(15.4)	0	0
Repurchase of common shares (in shares)							(3.0)
Dividends on common stock ($0.10 per share)	(8.1)	0	0	(8.1)	0	0
Other	0.2	0	0	0.2	0	0
Balance at Jun. 30, 2012	$ 1,073.9	$ 0.8	$ 521.3	$ 579.8	$ (28.3)	$ 0.3
Balance (in shares) at Jun. 30, 2012							80.2