Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 55,187	$ 63,899
Adjustments to reconcile net income to net cash flow from operating activities:
Depreciation and amortization	20,253	52,105
Stock-based compensation	3,599	5,103
Other (gains) losses on sales of assets and impairment charges	(1,010)	885
Equity losses in unconsolidated investments, net	1,238	1,469
Pension contributions, net of expense	(23,072)	(1,350)
Change in other assets and liabilities, net	(5,009)	17,806
Net cash flow from operating activities	51,186	139,917
Cash flows from investing activities:
Purchase of property and equipment	(10,643)	(17,959)
Payments for acquisitions of businesses, net of cash acquired	(325,903)	0
Payments for investments	(3,991)	(775)
Proceeds from investments	1,010	1,369
Proceeds from sale of businesses and assets	1,373	4,535
Net cash flow used for investing activities	(338,154)	(12,830)
Cash flows from financing activities:
Proceeds (payments) of borrowings under revolving credit facilities, net	220,000	(46,000)
Debt repayments	(33,062)	(33,062)
Dividends paid	(15,043)	(29,998)
Repurchases of common stock	0	(7,252)
Other, net	(4,630)	(8,144)
Net cash flow provided by (used for) financing activities	167,265	(124,456)
Decrease (increase) in cash and cash equivalents	(119,703)	2,631
Cash, cash equivalents and restricted cash from continuing operations, beginning of period	128,041	44,076
Cash, cash equivalents and restricted cash from discontinued operations, beginning of period	0	61,041
Balance of cash and cash equivalents, beginning of period	128,041	105,117
Cash, cash equivalents and restricted cash from continuing operations, end of period	8,338	40,133
Cash, cash equivalents and restricted cash from discontinued operations, end of period	0	67,615
Balance of cash and cash equivalents, end of period	$ 8,338	$ 107,748