CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock Member	Additional Paid In Capital Member	Retained Earnings Member	Accumulated Other Comprehensive Loss Member	Treasury Stock Member
Beginning Balance at Dec. 31, 2018		$ 49,187	$ 118,234	$ 2,191,471	$ (288,447)	$ (539,664)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	$ 55,593			55,593
Other Comprehensive Income (Loss), Net of Tax	9,925				9,925
Dividends paid/declared				(6,419)
Restricted stock			(5,491)			5,491
Stock Options Exercised			(519)			5,195
Share-based compensation			3,133			362
Repurchases of common stock						(12,471)
Other			(661)			661
Ending Balance at Mar. 31, 2019		49,187	114,696	2,266,902	(304,779)	(540,426)
Beginning Balance at Dec. 31, 2018		49,187	118,234	2,191,471	(288,447)	(539,664)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	(10,570)
Ending Balance at Dec. 31, 2019	1,774,372	49,187	116,070	2,497,111	(325,274)	(562,722)
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2018-02 [Member]				26,257	(26,257)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	51,761			51,761
Other Comprehensive Income (Loss), Net of Tax	(45,594)				(45,594)
Dividends paid/declared				(7,095)
Restricted stock			(4,115)			4,115
Stock Options Exercised			350			4,716
Share-based compensation			3,123			217
Repurchases of common stock						(112,013)
Other			(517)			517
Ending Balance at Mar. 31, 2020	$ 1,669,837	$ 49,187	$ 114,911	$ 2,541,777	$ (370,868)	$ (665,170)