Debt (Details) (USD $)	9 Months Ended			9 Months Ended		9 Months Ended		9 Months Ended			1 Months Ended			1 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Apr. 02, 2011 2011 Credit Agreement	Sep. 30, 2011 2011 term loan A	Apr. 02, 2011 2011 term loan A	Sep. 30, 2011 2011 term loan B	Apr. 02, 2011 2011 term loan B	Sep. 30, 2011 2011 Revolving Credit Facility	Sep. 30, 2011 Other.	Dec. 31, 2010 Other.	Apr. 30, 2011 2005 term loan	Apr. 02, 2011 2005 term loan	Dec. 31, 2010 2005 term loan	Apr. 30, 2011 2005 revolving credit facility	Apr. 02, 2011 2005 revolving credit facility
Debt instrument
Total debt	$ 2,424,739,000	$ 168,473,000		$ 935,000,000		$ 1,396,500,000			$ 93,239,000	$ 32,411,000			$ 136,062,000
Less current debt	(97,426,000)	(13,903,000)
Total long term debt	2,327,313,000	154,570,000
Weighted average stated interest rate (as a percent)				3.285%		4.00%
Debt repayment schedule excluding interest
2011	22,408,000			7,500,000		3,500,000			11,408,000
2012	100,378,000			52,500,000		14,000,000			33,878,000
2013	121,773,000			82,500,000		14,000,000			25,273,000
2014	143,493,000			112,500,000		14,000,000			16,993,000
2015	537,099,000			517,500,000		14,000,000			5,599,000
Thereafter	1,499,588,000			162,500,000		1,337,000,000			88,000
Walter Credit Agreement
Maximum amount of borrowings available under the credit agreement			2,725,000,000
Principal amount of credit agreement					950,000,000		1,400,000,000					450,000,000
Revolving credit facility, maximum borrowing capacity								375,000,000							300,000,000
Debt instrument, description of variable rate basis	LIBOR or CDOR										LIBOR			LIBOR
Percentage of interest rate in addition to LIBOR on debt instrument, maximum				3.00%		3.00%		3.00%				3.00%			4.00%
Quarterly principal payments of term loan											400,000
Commitment fee on the unused portion (as a percent)								0.50%						0.50%
Weighted average stated interest rate (as a percent)				3.285%		4.00%
Outstanding standby letters of credit								70,500,000
Availability for future borrowings under the Revolver								$ 304,500,000
Basis spread on variable rate, minimum (as a percent)				2.25%		2.75%		2.25%
Rate of LIBOR floor (as a percent)						1.00%