CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY Statement - USD ($) $ in Thousands		Total		Common Stock		Paid-in Capital		Treasury Stock		Retained Earnings	Accumulated Other Comprehensive Income (loss)		Accumulated Defined Benefit Plans Adjustment	Interest Rate Swap Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance, Beginning		$ 1,361,148		$ 145		$ 374,922		$ (445,118)		$ 1,697,618	$ (266,419)
Net earnings		65,420		0		0		0		65,420	0
Cumulative Effect on Retained Earnings, Net of Tax | Accounting Standards Update 2018-02		0	[1]	0	[1]	0	[1]	0	[1]	1,132	1,132	[1]
Cumulative Effect on Retained Earnings, Net of Tax | Accounting Standards Update 2014-09	[2]	(4,405)		0		0		0		(4,405)	0
Currency translation adjustment		21,802		0		0		0		0	21,802
Change in unrecognized pension benefit costs, net of tax		(8,874)
Change in unrecognized pension benefit costs, net of tax | Accounting Standards Update 2018-02		(8,387)		0		0		0		0	(8,387)
Unrealized gain on interest rate swaps, net of tax		6,555
Unrealized gain on interest rate swaps, net of tax | Accounting Standards Update 2018-02		4,936		0		0		0		0	4,936
Stock compensation		145		0		145		0		0	0
Other comprehensive income (loss), adopt of new accounting pronouncement														$ 1,600
Balance, Beginning		1,440,659		145		375,067		(445,118)		1,757,501	(246,936)
Balance, Beginning		1,665,203		145		377,419		(445,118)		2,009,233	(276,476)
Net earnings		69,013		0		0		0		69,013	0
Cumulative Effect on Retained Earnings, Net of Tax | Accounting Standards Update 2017-12	[3]	0		0		0		0		(11)	11
Currency translation adjustment		10,683		0		0		0		0	10,683
Change in unrecognized pension benefit costs, net of tax		(5,263)
Change in unrecognized pension benefit costs, net of tax | Accounting Standards Update 2018-02		(5,263)		0		0		0		0	(5,263)
Unrealized gain on interest rate swaps, net of tax		(9,367)
Unrealized gain on interest rate swaps, net of tax | Accounting Standards Update 2018-02		(9,378)		0		0		0		0	(9,378)
Stock compensation		1,069		0		1,069		0		0	0
Purchase of treasury stock		(5,268)		0		0		(5,268)		0	0
Other comprehensive income (loss), adopt of new accounting pronouncement													$ (500)
Balance, Beginning		$ 1,726,059		$ 145		$ 378,488		$ (450,386)		$ 2,078,235	$ (280,423)

[1] (1) As of December 31, 2017, the company adopted ASU No. 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The adoption of this guidance resulted in the reclassification of $1.1 million, including $1.6 million related to interest rate swap and $(0.5) million related to pensions, of stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 from accumulated other comprehensive income to retained earnings.

[2] (2) As of December 31, 2017, the company adopted ASU No. 2014-09, Revenue from Contracts with Customers (ASC 606) using the modified retrospective method to contracts that were not completed as of December 30, 2017. The adoption of this guidance resulted in the recognition of $4.4 million as an adjustment to the opening balance of retained earnings.

[3] (3) As of December 30, 2018, the company adopted ASU No. 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities" using the modified retrospective method. The adoption of this guidance resulted in the recognition of less than $0.1 million as an adjustment to the opening balance of retained earnings.