Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows from Operating Activities:
Net income (loss)	$ 5.6	$ 8.7
Adjustments to reconcile net income (loss) to net cash provided by (used in) operations:
Depreciation and amortization	13.6	10.9
Loss (gain) on asset transactions, net	(0.5)	(2.6)
Share-based compensation expense	1.5	1.4
(Income) loss from affiliates, net of distributions of income	(2.9)	(0.8)
Changes in operating assets and liabilities:
Trade, contracts retention, and other contract receivables	7.0	(11.0)
Inventories	0.0	(2.5)
Prepaid expenses, income tax receivable and other assets	2.4	(4.5)
Development/other property inventory	(3.2)	27.1
Accrued pension and post-retirement benefits	0.6	1.6
Accounts payable	(3.5)	(4.8)
Accrued and other liabilities	(1.7)	1.1
Net cash provided by (used in) operations	18.9	24.6
Cash Flows from Investing Activities:
Capital expenditures for acquisitions	0.0	(42.4)
Capital expenditures for property, plant and equipment	(6.2)	(16.6)
Proceeds from disposal of property, investments and other assets	5.9	2.7
Payments for purchases of investments in affiliates and other investments	0.0	(2.5)
Distributions of capital from investments in affiliates and other investments	3.2	6.6
Net cash provided by (used in) investing activities	2.9	(52.2)
Cash Flows from Financing Activities:
Proceeds from issuance of notes payable and other debt	108.0	41.4
Payments of notes payable and other debt and deferred financing costs	(44.2)	(49.2)
Borrowings (payments) on line-of-credit agreement, net	51.4	3.6
Cash dividends paid	(13.8)	(10.5)
Proceeds from issuance (repurchase) of capital stock and other, net	(0.9)	(1.7)
Net cash provided by (used in) financing activities	100.5	(16.4)
Cash, Cash Equivalents and Restricted Cash
Net increase (decrease) in cash, cash equivalents and restricted cash	122.3	(44.0)
Balance, beginning of period	15.4	234.9
Balance, end of period	137.7	190.9
Other Cash Flow Information:
Interest paid, net of capitalized interest	(7.0)	(8.4)
Income tax (payments)/refunds, net	0.5	2.6
Noncash Investing and Financing Activities:
Capital expenditures included in accounts payable and accrued and other liabilities	2.6	1.2
Right-of-use ("ROU") assets and corresponding lease liability recorded upon ASC 842 adoption	0.0	31.0
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents, beginning of period	15.2	11.4
Restricted cash, beginning of period	0.2	223.5
Cash and cash equivalents, end of period	131.6	3.0
Restricted cash, end of period	6.1	187.9
Cash, cash equivalents and restricted cash	$ 137.7	$ 234.9