Operating Property and Equipment

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

OPERATING PROPERTY AND EQUIPMENT

OPERATING PROPERTY AND EQUIPMENT

	Estimated Useful  Lives	December 31,
		2017			2016
	(In years)	(In thousands)
Land	—	$	217,885		212,660
Buildings and improvements	10 — 40	822,931			808,909
Machinery and equipment	3 — 10	797,084			737,899
Other	3 — 10	131,181			114,442
		1,969,081			1,873,910
Accumulated depreciation		(1,192,377		)	(1,128,040	)
Total		$	776,704		745,870

Depreciation expense was $94 million, $88 million and $84 million in 2017, 2016 and 2015, respectively.