Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash Flows from Operating Activities:
Net income	$ 260.6	$ 219.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, and amortization of intangibles	186.2	176.3
Amortization of deferred financing costs	4.0	3.8
Share-based compensation expense	10.2	10.3
Deferred income tax provision	3.9	1.3
Pension and post retirement benefits expense, net of contributions	4.9	8.7
Other, net	0.7	4.2
(Increase) decrease in assets —
Accounts receivable	(66.1)	(26.9)
Inventories	(10.8)	5.5
Prepaid expenses and other current assets	(20.0)	(27.5)
Increase (decrease) in liabilities —
Accounts payable	18.8	(4.0)
Accrued liabilities	(24.1)	(23.3)
Federal and state income taxes payable / receivable	17.3	28.2
Net cash provided by operating activities	385.6	376.2
Cash Flows from Investing Activities:
Additions to property, plant, and equipment	(139.4)	(121.8)
Additions to other long term assets	(5.5)	(6.2)
Proceeds from disposals	2.9	0.3
Other, net	1.1
Net cash used for investing activities	(140.9)	(127.7)
Cash Flows from Financing Activities:
Repayments of debt and capital lease obligations	(33.7)	(3.8)
Common stock dividends paid	(118.8)	(104.9)
Repurchases of common stock	0.0	(100.3)
Shares withheld to cover employee restricted stock taxes	(10.5)	(10.1)
Net cash used for financing activities	(163.0)	(219.1)
Net increase in cash and cash equivalents	81.7	29.4
Cash and cash equivalents, beginning of period	239.3	184.2
Cash and cash equivalents, end of period	$ 321.0	$ 213.6