Other Income, Net (Tables)

12 Months Ended

Dec. 31, 2016

Other Income and Expenses [Abstract]

Other Income, Net

Other income, net for the years ended Dec. 31 consisted of the following:

(Thousands of Dollars)	2016			2015			2014
Interest income	$	8,342		$	5,737		$	7,353
Other nonoperating income	2,981			3,514			4,866
Insurance policy expense	(3,373		)	(3,851		)	(6,923		)
Other income, net	$	7,950		$	5,400		$	5,296