Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Cash Flows [Abstract]
Net income (loss)	$ 67,235	$ (82,477)	$ 10,529
Net (loss) income from discontinued operations, net of tax	0	(15,840)	1,072
Income (loss) from continuing operations	67,235	(66,637)	9,457
Adjustments to reconcile income (loss) from continuing operations to net cash flows from operating activities:
Depreciation and amortization	58,581	51,952	32,180
Impairment of goodwill and intangibles	0	24,613	0
Losses (gains) on sale of property and equipment	543	483	(2,872)
Deferred income taxes	39,267	(26,831)	5,384
Excess tax benefits of share-based compensation plans	0	0	(8,352)
Stock and deferred compensation plans	11,127	10,125	6,992
Pension expense, net of payments	4,936	58,358	4,433
Other changes in certain working capital accounts, net	(35,865)	(43,790)	29,243
Miscellaneous, net	669	555	1,830
Net cash provided by continuing operating activities	146,493	8,828	78,295
Net cash provided by discontinued operating activities	0	42	23,760
Net operating activities	146,493	8,870	102,055
Cash Flows from Investing Activities:
Acquisitions, net of cash acquired	43,500	46,838	149,284
Proceeds from sale of property and equipment	56	1,722	5,856
Proceeds from sale of property held for sale	0	14,500	0
Additions to property and equipment	(27,948)	(23,105)	(16,300)
Purchase of investments	(2,128)	(7,658)	(2,652)
Miscellaneous, net	92	1,578	2,007
Net cash used in continuing investing activities	(73,428)	(59,801)	(160,373)
Net cash used in discontinued investing activities	0	(1,561)	(1,564)
Net investing activities	(73,428)	(61,362)	(161,937)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt	0	200,000	0
Payments on long-term debt	(6,635)	(122,406)	(2,000)
Payments of financing costs	0	(2,592)	(483)
Dividends paid	0	(59,523)	0
Repurchase of Class A Common shares	(44,401)	(16,222)	(21,237)
Proceeds from employee stock options	4,641	7,249	16,579
Tax payments related to shares withheld for vested stock and RSUs	(2,681)	(5,237)	(4,261)
Excess tax benefits from stock compensation plans	0	0	8,352
Miscellaneous, net	(4,258)	575	(1,264)
Net cash provided by (used in) continuing financing activities	(53,334)	1,844	(4,314)
Increase (Decrease) in cash, cash equivalents and restricted cash	19,731	(50,648)	(64,196)
Cash, cash equivalents and restricted cash:
Beginning of year	114,621	165,269	229,465
End of year	$ 134,352	$ 114,621	$ 165,269