Variable Interest Entities - Schedule of Consolidated VIEs Assets and Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 77,303	$ 100,073
Accounts receivable, net	386,191	361,451
Other current assets	147,312	134,476
Total current assets	610,806	596,000
Property and equipment, net	2,376,059	2,266,610
Goodwill	2,261,026	2,225,962	$ 2,222,805
Intangible assets, net	73,352	73,278
Operating lease right-of-use assets	121,346	117,780
Total assets	5,517,247	5,358,841
Accounts payable	156,130	156,132
Accrued salaries and benefits	118,005	141,901
Current portion of operating lease liabilities	26,815	26,268
Other accrued liabilities	119,911	532,261
Total current liabilities	482,313	885,781
Operating lease liabilities	103,352	100,808
Other liabilities	146,404	140,113
Total liabilities	2,541,892	2,471,181
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents	63,571	55,149
Accounts receivable, net	36,746	34,910
Other current assets	2,739	2,193
Total current assets	103,056	92,252
Property and equipment, net	476,150	438,965
Goodwill	42,384	42,384
Intangible assets, net	18,313	18,295
Operating lease right-of-use assets	10,231	5,948
Total assets	650,134	597,844
Accounts payable	8,611	8,235
Accrued salaries and benefits	6,714	9,909
Current portion of operating lease liabilities	554	273
Other accrued liabilities	3,097	2,385
Total current liabilities	18,976	20,802
Operating lease liabilities	10,208	6,160
Total liabilities	$ 29,184	$ 26,962