Goodwill and Other Intangible Assets - Goodwill and Accumulated Goodwill Impairment Losses (Details) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 2,640,500,000		$ 2,640,500,000
Accumulated goodwill impairment losses	(1,369,800,000)		(1,369,800,000)
Goodwill, net, beginning balance	1,270,700,000		1,270,700,000
Impairment losses during year-to-date period	(113,000,000.0)	$ 0	(113,000,000.0)	$ 0
Goodwill, gross, ending balance			2,640,500,000
Accumulated goodwill impairment losses			(1,482,800,000)
Goodwill, net, ending balance			1,157,700,000
Operating segments | Northeast segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	914,300,000		914,300,000
Accumulated goodwill impairment losses	(717,900,000)		(717,900,000)
Goodwill, net, beginning balance	196,400,000		196,400,000
Impairment losses during year-to-date period	(43,500,000)		(43,500,000)
Goodwill, gross, ending balance			914,300,000
Accumulated goodwill impairment losses			(761,400,000)
Goodwill, net, ending balance			152,900,000
Operating segments | South segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	236,600,000		236,600,000
Accumulated goodwill impairment losses	(52,000,000.0)		(52,000,000.0)
Goodwill, net, beginning balance	184,600,000		184,600,000
Impairment losses during year-to-date period	(9,000,000.0)		(9,000,000.0)
Goodwill, gross, ending balance			236,600,000
Accumulated goodwill impairment losses			(61,000,000.0)
Goodwill, net, ending balance			175,600,000
Operating segments | West segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	216,800,000		216,800,000
Accumulated goodwill impairment losses	(16,600,000)		(16,600,000)
Goodwill, net, beginning balance	200,200,000		200,200,000
Impairment losses during year-to-date period			0
Goodwill, gross, ending balance			216,800,000
Accumulated goodwill impairment losses			(16,600,000)
Goodwill, net, ending balance			200,200,000
Operating segments | Midwest segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	1,116,700,000		1,116,700,000
Accumulated goodwill impairment losses	(495,600,000)		(495,600,000)
Goodwill, net, beginning balance	621,100,000		621,100,000
Impairment losses during year-to-date period	(60,500,000)		(60,500,000)
Goodwill, gross, ending balance			1,116,700,000
Accumulated goodwill impairment losses			(556,100,000)
Goodwill, net, ending balance			560,600,000
Other
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	156,100,000		156,100,000
Accumulated goodwill impairment losses	(87,700,000)		(87,700,000)
Goodwill, net, beginning balance	$ 68,400,000		68,400,000
Impairment losses during year-to-date period			0
Goodwill, gross, ending balance			156,100,000
Accumulated goodwill impairment losses			(87,700,000)
Goodwill, net, ending balance			$ 68,400,000