CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands		Common Stock [Member]	Treasury Stock [Member]	Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2012		$ 219,023		$ 45,156	$ (56,967)	$ 147,744	$ 354,956
Balance (in shares) at Dec. 31, 2012		219,023,000
Increase (Decrease) in Shareholders' Equity
Net Income						$ 123,330	123,330
Pension Liability Adjustment					28,102		28,102
Foreign Currency Translation Adjustments					$ (2,906)		(2,906)
Cash Dividends						$ (65,658)	(65,658)
Common Stock Purchased	[1]	$ (512)				(7,856)	(8,368)
Common Stock Purchased (in shares)	[1]	(512,000)
Stock Compensation		$ 612		$ 10,020		(205)	10,427
Stock Compensation (in shares)		612,000
Employee Stock Buybacks and Common Stock Options Exercised		$ (326)		(5,133)		109	(5,350)
Employee Stock Buybacks and Common Stock Options Exercised (in shares)		(326,000)
Excess Tax Benefit on Restricted Stock, Dividend Compensation and Non-Qualified Stock Options				3,722			3,722
Balance at Dec. 31, 2013		$ 218,797		53,765	$ (31,771)	197,464	438,255
Balance (in shares) at Dec. 31, 2013		218,797,000
Increase (Decrease) in Shareholders' Equity
Net Income						137,664	137,664
Pension Liability Adjustment					(25,575)		(25,575)
Foreign Currency Translation Adjustments					$ (8,142)		(8,142)
Cash Dividends						(75,750)	(75,750)
Common Stock Issued for Acquisitions		$ 585	$ 290	15,831		(292)	16,414
Common Stock Issued for Acquisitions (in shares)		585,000	290,000
Common Stock Purchased	[1]	$ (920)	$ (590)	(15,831)		(12,004)	(29,345)
Common Stock Purchased (in shares)	[1]	(920,000)	(590,000)
Treasury Shares		$ (100)	$ 100
Treasury Shares (in shares)		(100,000)	100,000
Stock Compensation		$ 439		10,286		(146)	10,579
Stock Compensation (in shares)		439,000
Employee Stock Buybacks and Common Stock Options Exercised		$ (318)		(5,956)		106	(6,168)
Employee Stock Buybacks and Common Stock Options Exercised (in shares)		(318,000)
Excess Tax Benefit on Restricted Stock, Dividend Compensation and Non-Qualified Stock Options				4,744			4,744
Balance at Dec. 31, 2014		$ 218,483	$ (200)	62,839	$ (65,488)	247,042	462,676
Balance (in shares) at Dec. 31, 2014		218,483,000	(200,000)
Increase (Decrease) in Shareholders' Equity
Net Income						152,149	152,149
Pension Liability Adjustment					9,070		9,070
Foreign Currency Translation Adjustments					(14,760)		(14,760)
Cash Dividends						(91,755)	(91,755)
Common Stock Purchased	[1]	$ (19)				(416)	(435)
Common Stock Purchased (in shares)	[1]	(19,000)
Stock Compensation		$ 597		11,731		(218)	12,110
Stock Compensation (in shares)		597,000
Employee Stock Buybacks and Common Stock Options Exercised		$ (308)		(6,754)		90	(6,972)
Employee Stock Buybacks and Common Stock Options Exercised (in shares)		(308,000)
Excess Tax Benefit on Restricted Stock, Dividend Compensation and Non-Qualified Stock Options				1,946			1,946
Balance at Dec. 31, 2015		$ 218,753	$ (200)	$ 69,762	$ (71,178)	$ 306,892	$ 524,029
Balance (in shares) at Dec. 31, 2015		218,753,000	(200,000)

[1] Charges to Retained Earnings are from purchases of the Company's Common Stock.