CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net unrealized loss, net of tax expense	$ 513	$ 0	$ 805	$ 0
Reclassification of net realized loss, net of tax benefit	87	134	481	242
Pension and other postretirement benefits activity, net of tax expense (benefit)	334	506	90	218
APS
Net unrealized loss, net of tax expense	0	0	292	0
Reclassification of net realized loss, net of tax benefit	87	134	481	242
Pension and other postretirement benefits activity, net of tax expense (benefit)	$ 361	$ 544	$ 124	$ 297