Goodwill and Other Intangible Assets - Goodwill and Accumulated Goodwill Impairment Losses (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 2,510,173
Accumulated goodwill impairment losses, beginning balance	(1,281,751)
Goodwill, net, beginning balance	1,228,422
Goodwill acquired during year	39,457
Other	11,617
Goodwill, gross, ending balance	2,561,247
Accumulated goodwill impairment losses, ending balance	(1,281,751)
Goodwill, net, ending balance	1,279,496
Operating segments | Northeast segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	848,424
Accumulated goodwill impairment losses, beginning balance	(707,593)
Goodwill, net, beginning balance	140,831
Goodwill acquired during year	0
Other	(2,000)
Goodwill, gross, ending balance	846,424
Accumulated goodwill impairment losses, ending balance	(707,593)
Goodwill, net, ending balance	138,831
Operating segments | South segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	185,158
Accumulated goodwill impairment losses, beginning balance	(34,522)
Goodwill, net, beginning balance	150,636
Goodwill acquired during year	39,457
Other	5,100
Goodwill, gross, ending balance	229,715
Accumulated goodwill impairment losses, ending balance	(34,522)
Goodwill, net, ending balance	195,193
Operating segments | West segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	210,423
Accumulated goodwill impairment losses, beginning balance	(16,633)
Goodwill, net, beginning balance	193,790
Goodwill acquired during year	0
Other	4,117
Goodwill, gross, ending balance	214,540
Accumulated goodwill impairment losses, ending balance	(16,633)
Goodwill, net, ending balance	197,907
Operating segments | Midwest segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	1,110,052
Accumulated goodwill impairment losses, beginning balance	(435,283)
Goodwill, net, beginning balance	674,769
Goodwill acquired during year	0
Other	4,400
Goodwill, gross, ending balance	1,114,452
Accumulated goodwill impairment losses, ending balance	(435,283)
Goodwill, net, ending balance	679,169
Other
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	156,116
Accumulated goodwill impairment losses, beginning balance	(87,720)
Goodwill, net, beginning balance	68,396
Goodwill acquired during year	0
Other	0
Goodwill, gross, ending balance	156,116
Accumulated goodwill impairment losses, ending balance	(87,720)
Goodwill, net, ending balance	$ 68,396