CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Income	$ 196,960	$ 162,703	$ 164,172
Other comprehensive income (loss), net of tax:
Reclassification of net losses (gains) on derivative instruments	498	371	(1,338)
Postretirement medical liability adjustment	213	773	195
Foreign currency translation adjustment	270	(202)	25
Total Other Comprehensive Income (Loss)	981	942	(1,118)
Comprehensive Income	$ 197,941	$ 163,645	$ 163,054

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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