CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 184,708	$ 246,879
Accounts receivable, net of allowances aggregating $31,426 and $25,661, respectively	496,004	557,131
Unbilled accounts receivable	25,940	40,775
Deferred costs	18,758	19,018
Inventories and supplies	149,521	168,663
Prepaid expenses and other current assets	46,265	57,435
Deferred tax assets	0	36,532
Total current assets	921,196	1,126,433
Property, plant and equipment, net	1,532,467	1,558,834
Other assets:
Deferred financing costs	1,847	2,725
Goodwill	453,105	452,669
Permits and other intangibles, net	506,818	530,080
Other	15,995	18,682
Total other assets	977,765	1,004,156
Total assets	3,431,428	3,689,423
Current liabilities:
Current portion of capital lease obligations	0	536
Accounts payable	241,183	267,329
Deferred revenue	61,882	62,966
Accrued expenses	193,660	219,549
Current portion of closure, post-closure and remedial liabilities	20,395	22,091
Total current liabilities	517,120	572,471
Other liabilities:
Closure and post-closure liabilities, less current portion of $7,229 and $4,999, respectively	49,020	45,702
Remedial liabilities, less current portion of $13,166 and $17,092, respectively	118,826	138,029
Long-term obligations	1,382,543	1,380,145
Deferred taxes, unrecognized tax benefits and other long-term liabilities	267,637	290,205
Total other liabilities	$ 1,818,026	$ 1,854,081
Commitments and contingent liabilities
Stockholders' equity:
Authorized 80,000,000 shares; issued and outstanding 57,593,201 and 58,903,482 shares, respectively	$ 576	$ 589
Shares held under employee participation plan	(469)	(469)
Additional paid-in capital	738,401	805,029
Accumulated other comprehensive loss	(254,892)	(110,842)
Accumulated earnings	612,666	568,564
Total stockholders' equity	1,096,282	1,262,871
Total liabilities and stockholders' equity	$ 3,431,428	$ 3,689,423