Debt (Details) (USD $)	6 Months Ended				6 Months Ended		6 Months Ended		6 Months Ended			1 Months Ended				1 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 2011 Credit Agreement	Apr. 02, 2011 2011 Credit Agreement	Jun. 30, 2011 2011 term loan A	Apr. 02, 2011 2011 term loan A	Jun. 30, 2011 2011 term loan B	Apr. 02, 2011 2011 term loan B	Jun. 30, 2011 2011 Revolving Credit Facility	Jun. 30, 2011 Other.	Dec. 31, 2010 Other.	Apr. 30, 2011 2005 term loan	Jun. 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	$ 2,468,745,000	$ 168,473,000			$ 942,500,000		$ 1,400,000,000		$ 20,736,000	$ 105,509,000	$ 32,411,000				$ 136,062,000
Less current debt	(81,976,000)	(13,903,000)
Total long term debt	2,386,769,000	154,570,000
Weighted average stated interest rate (as a percent)					3.20%		4.00%		4.20%				2.51%
Debt repayment schedule excluding interest
2011	42,589,000				15,000,000		7,000,000			20,589,000
2012	101,749,000				52,500,000		14,000,000			35,249,000
2013	122,385,000				82,500,000		14,000,000			25,885,000
2014	144,154,000				112,500,000		14,000,000			17,654,000
2015	537,540,000				517,500,000		14,000,000			6,040,000
Thereafter	1,520,328,000				162,500,000		1,337,000,000		20,736,000	92,000
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 (as a percent)					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%
Term loan outstanding			20,700,000
Weighted average stated interest rate (as a percent)					3.20%		4.00%		4.20%				2.51%
Outstanding standby letters of credit			64,600,000
Availability for future borrowings under standby letters of credit			$ 289,700,000
Basis spread on variable rate, minimum (as a percent)					2.25%		2.75%		2.25%
Rate of LIBOR floor (as a percent)							1.00%