Land and land improvements

$

54,003

$

50,679

$

52,339

Buildings and improvements

240,666

238,376

238,709

Machinery and equipment

519,968

498,540

502,223

Office equipment, furniture, vehicles and computer software

16,032

15,505

15,604

Construction in progress

13,198

9,499

16,177

Property, plant and equipment, cost

843,867

812,599

825,052

Less: accumulated depreciation

(519,851

)

(486,739

)

(500,284

)

Property, plant and equipment, net

$

324,016

$

325,860

$

324,768