CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 401,992	$ 444,698
Short-term marketable securities	91,294	106,101
Accounts receivable, net of allowances aggregating $50,639 and $42,209, respectively	1,089,832	983,111
Unbilled accounts receivable	187,148	107,859
Inventories and supplies	365,356	327,511
Prepaid expenses and other current assets	93,440	82,939
Total current assets	2,229,062	2,052,219
Property, plant and equipment, net	2,408,647	2,193,318
Other assets:
Operating lease right-of-use assets	214,858	187,060
Goodwill	1,482,085	1,287,736
Permits and other intangibles, net	727,463	602,797
Other long-term assets	74,833	59,739
Total other assets	2,499,239	2,137,332
Total assets	7,136,948	6,382,869
Current liabilities:
Current portion of long-term debt	15,102	10,000
Accounts payable	447,940	451,806
Deferred revenue	108,035	95,230
Accrued expenses and other current liabilities	392,708	397,157
Current portion of closure, post-closure and remedial liabilities	31,954	26,914
Current portion of operating lease liabilities	65,901	56,430
Total current liabilities	1,061,640	1,037,537
Other liabilities:
Closure and post-closure liabilities, less current portion of $15,813 and $13,556, respectively	103,299	105,044
Remedial liabilities, less current portion of $16,141 and $13,358, respectively	95,458	97,885
Long-term debt, less current portion	2,775,837	2,291,717
Operating lease liabilities, less current portion	152,328	131,743
Deferred tax liabilities	360,861	353,107
Other long-term liabilities	145,804	118,330
Total other liabilities	3,633,587	3,097,826
Commitments and contingent liabilities (See Note 15)
Stockholders’ equity:
Common stock	539	539
Additional paid-in capital	459,982	459,728
Accumulated other comprehensive loss	(184,490)	(175,339)
Retained earnings	2,165,690	1,962,578
Total stockholders’ equity	2,441,721	2,247,506
Total liabilities and stockholders’ equity	$ 7,136,948	$ 6,382,869
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01