Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Summary of property, plant and equipment

Depreciation is calculated by the straight-line method over the estimated useful lives of depreciable assets which are as follows:

Buildings and improvements	10 to 40 years
Machinery and equipment	2 to 7 years
Software and computer equipment	3 to 5 years
Furniture, fixtures and other equipment	4 to 10 years

Property, plant and equipment consist of the following:

	December 31,
	2020		2019
	(In thousands)
Land	$	221,304	$	219,785
Buildings and improvements	1,625,355		1,571,653
Machinery and equipment	5,736,797		5,303,729
Finance lease machinery and equipment	40,856		34,158
Furniture, fixtures and other equipment	20,774		19,740
Software and computer equipment	231,171		220,264
Construction in progress	48,602		12,593
Total property, plant and equipment	7,924,859		7,381,922
Less accumulated depreciation and amortization	(5,358,857)		(4,977,072)
Total property, plant and equipment, net	$	2,566,002	$	2,404,850

The following table summarizes our depreciation expense:

	For the Year Ended December 31,
	2020		2019		2018
	(In thousands)
Depreciation expense	$	509,770	$	522,011	$	570,304