Consolidated Condensed Statements of Income (Parenthetical) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Consolidated Condensed Statements Of Income [Abstract]
Pension and post-retirement plans expense reclassified from accumulated other comprehensive income	$ 1,800,000	$ 1,800,000
Income tax benefit reclassified from accumulated other comprehensive income	(200,000)	700,000
Available-for-sale expense reclassified from accumulated other comprehensive income	1,654,000	0
Cash Flow hedge reclassification adjustment from accumulated other comprehensive income	$ 600,000	$ 0