Other Income, Net (Tables)

12 Months Ended

Dec. 31, 2015

Other Income and Expenses [Abstract]

Other Income, Net

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

(Thousands of Dollars)	2015			2014			2013
Interest income	$	5,737		$	7,353		$	8,343
Other nonoperating income	3,514			4,866			3,025
Insurance policy expense	(3,851		)	(6,923		)	(8,292		)
Other nonoperating expense	—			—			(104		)
Other income, net	$	5,400		$	5,296		$	2,972