Short-term Debt and Credit Lines (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of Short-Term Debt

Short-term debt at December 31, 2017 and 2016 consisted of:

	2017		2016
	(In thousands)
Notes payable to banks	$	8,300	$	8,200
Commercial paper	36,250		29,750
Total short-term debt	$	44,550	$	37,950