Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 19,067	$ 46,360
Short-term investments	750	750
Accounts receivable, net	178,948	160,167
Inventories	187,018	173,999
Income taxes receivable	4,191	6,929
Other current assets	36,788	29,178
Total current assets	426,762	417,383
Property, plant and equipment, net	531,345	536,686
Goodwill	296,186	304,805
Intangibles, net	184,631	203,473
Deferred income tax assets, net	51,556	54,302
Other non-current assets	39,394	34,603
Total assets	1,529,874	1,551,252
Current liabilities:
Accounts payable	112,247	118,424
Accrued expenses	66,757	68,786
Current portion of long-term debt	3,112	4,000
Income taxes payable	790	3,849
Total current liabilities	182,906	195,059
Long-term debt (less current portion)	669,620	679,552
Non-current income tax liabilities	15,195	5,731
Deferred income tax liabilities, net	23,088	28,539
Embedded derivative liability	8,375	4,685
Other non-current liabilities	55,566	47,269
Commitments and contingencies (Note 21)
Mezzanine equity:
Redeemable preferred shares, $0.01 par value, 1,000,000 shares authorized, 150,000 shares outstanding at June 30, 2018 and December 31, 2017	153,153	144,694
European non-controlling redeemable equity	52,599
Shareholders' equity:
Common stock, $0.01 par value Authorized-100,000,000 shares; Issued and outstanding - 25,011,730 shares at June 30, 2018 (24,917,025 shares at December 31, 2017)	87,305	89,755
Accumulated other comprehensive loss	(110,249)	(89,121)
Retained earnings	392,316	393,146
Superior shareholders' equity	369,372	393,780
Noncontrolling interests		51,943
Total shareholders' equity	369,372	445,723
Total liabilities, mezzanine and shareholders' equity	$ 1,529,874	$ 1,551,252