Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net income	$ 97,224	$ 107,362
Other comprehensive income (loss), net of tax:
Benefit plan liability adjustments - net gain (net of tax of $(17) and $0, respectively	55	0
Reclassification adjustments of benefit plan liability - prior service cost (net of tax of $7 and $5, respectively)	(23)	(14)
Reclassification adjustments of benefit plan liability - net gain (net of tax of $(95) and $(53), respectively)	502	167
Other comprehensive income, net of tax	1,273	457
Comprehensive income	98,497	107,819
Net Income (Loss) Attributable to Noncontrolling Interest	4,050	3,554
Comprehensive income available for common stock	94,447	104,265
Interest rate swaps
Other comprehensive income (loss), net of tax:
Reclassification of net realized (gains) losses	543	550
Commodity Contract
Other comprehensive income (loss), net of tax:
Reclassification of net realized (gains) losses	371	(426)
Net unrealized gains (losses) on commodity derivatives (net of tax of $54 and $(54), respectively)	$ (175)	$ 180