Statement of Consolidated Cash Flows (Unaudited) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income		$ 47.2	$ 46.4
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, plant and equipment		22.6	20.7
Amortization of definite-lived intangible assets		1.4	0.7
Amortization of debt discount and debt issuance costs		0.6	0.5
Deferred income taxes		18.3	17.8
Non-cash equity compensation		6.1	5.7
Gain on disposition of available for sale securities		(0.4)	(1.5)
Non-cash asset impairment charge		0.1	0.1
(Gain) loss on disposition of property, plant and equipment		(0.2)	0.1
Other non-cash changes in assets and liabilities		6.1	15.7
Changes in operating assets and liabilities:
Trade and other receivables		2.2	(29.6)
Contract assets		8.0	3.0
Inventories		(16.0)	(10.0)
Prepaid expenses and other current assets		(4.3)	(3.0)
Accounts payable		(13.4)	43.9
Accrued liabilities		(6.6)	(10.8)
Annual variable cash contributions to VEBAs		(2.1)	(15.7)
Long-term assets and liabilities, net		0.9	0.0
Net cash provided by operating activities		70.5	84.0
Cash flows from investing activities
Capital expenditures		(29.9)	(35.8)
Purchase of available for sale securities		(33.0)	(24.0)
Purchase of equity securities		(0.7)	(0.9)
Proceeds from disposition of available for sale securities		45.7	136.6
Proceeds from disposition of property, plant and equipment		0.2	0.0
Net cash (used in) provided by investing activities	[1]	(17.7)	75.9
Cash flows from financing activities
Repayment of finance lease		(0.6)	(0.3)
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares		(6.2)	(6.9)
Repurchase of common stock		(28.6)	(18.9)
Cash dividends and dividend equivalents paid		(20.1)	(19.3)
Net cash used in financing activities	[1]	(55.5)	(45.4)
Net (decrease) increase in cash, cash equivalents and restricted cash during the period		(2.7)	114.5
Cash, cash equivalents and restricted cash at beginning of period		139.6	64.3
Cash, cash equivalents and restricted cash at end of period		$ 136.9	$ 178.8

[1] See Note 12 for supplemental cash flow information.