Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income	$ 107,362	$ 136,634
Other comprehensive income (loss), net of tax:
Reclassification adjustments of benefit plan liability - prior service cost	(14)	(35)
Reclassification adjustments of benefit plan liability - net gain (loss)	167	486
Other comprehensive income, net of tax	457	1,260
Comprehensive income	107,819	137,894
Less: comprehensive income attributable to noncontrolling interest	(3,554)	(3,630)
Comprehensive income available for common stock	104,265	134,264
Interest rate swaps
Other comprehensive income (loss), net of tax:
Reclassification of net realized (gains) losses	550	561
Commodity Contract
Other comprehensive income (loss), net of tax:
Reclassification of net realized (gains) losses	(426)	476
Net unrealized gains (losses)	$ 180	$ (228)