CONSOLIDATED STATEMENT OF SHAREHOLDERS EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Tax effect of gain (losses) on derivatives qualifying as hedges	$ 2,017	$ (227)	$ 463
Tax effect of pension liability and postretirement adjustment	$ (1,583)	$ 3,049	$ (29,452)
Cash dividends declared, per share	$ 2.84	$ 2.66	$ 2.40