CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Cash flows from operating activities:
Net income	$ 24,214	$ 33,156	$ 59,122
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation and amortization	75,980	56,890	51,234
Provision for doubtful accounts	2,454	1,199	1,676
Amortization and write off of debt discount and debt issuance costs	505	458	114
Stock-based compensation	6,410	4,975	4,323
Deferred income taxes	(5,636)	17,869	(113)
Bargain purchase gain	(7,304)
(Gain) Loss on disposition of long-lived assets	27	(2,823)
Gain on sale of discontinued operations		(1,092)	(1,102)
Impairment of long-lived assets	11,425
Pension funding required by Innovative acquisition	(22,494)
Other non-cash activity	566
Loss on deconsolidation of subsidiary		19,937
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	2,601	11,744	(15,264)
Materials and supplies, prepayments, and other current assets	(8,410)	(1,094)	(4,817)
Income tax receivable			(2,620)
Accounts payable and accrued liabilities, advance payments and deposits and other current liabilities	6,522	(2,385)	7,629
Accrued taxes	21,547	9,740	(15,650)
Other assets	(12,122)	(134)	(1,833)
Other liabilities	15,371	(9,360)
Net cash provided by operating activities of continuing operations	111,656	139,080	82,699
Net cash provided by operating activities of discontinued operations		158	(4,719)
Net cash provided by operating activities	111,656	139,238	77,980
Cash flows from investing activities:
Capital expenditures	(124,282)	(64,753)	(58,300)
Purchase of marketable securities	(2,000)
Acquisition of businesses, net of acquired cash of $12.6 million, $0.0 million, and $6.6 million	(146,395)	(11,968)	(50,361)
Restricted cash acquired from acquisition of business			(5,884)
Purchases of spectrum licenses and other intangible assets, including deposits	(10,860)
Acquisition of non-controlling interest in subsidiary	(7,045)
Purchase of short-term investments	(7,422)
Change in restricted cash	(12,108)	38,877	38,707
Proceeds from disposition of long-lived assets	1,424	5,873	1,371
Net cash used in investing activities of continuing operations	(308,688)	(31,971)	(74,467)
Cash flows from financing activities:
Dividends paid on common stock	(20,965)	(19,070)	(17,488)
Proceeds from issuance of debt	125,800
Distribution to non-controlling stockholders	(8,632)	(16,514)	(16,331)
Payment of debt issuance costs	(2,763)	(892)	(1,945)
Proceeds from stock option exercises	649	1,998	1,129
Principal repayments of term loan	(33,564)	(6,017)
Purchase of common stock	(4,114)	(1,893)	(1,665)
Repurchases of non-controlling interests	(3,485)		(104)
Investments made by minority shareholders in consolidated affiliates	22,408	950	2,500
Net cash provided by (used in) financing activities	75,334	(41,438)	(33,904)
Effect of foreign currency exchange rates on cash and cash equivalents	(626)
Net change in cash and cash equivalents	(122,324)	65,829	(30,391)
Cash and cash equivalents, beginning of period	392,045	326,216	356,607
Cash and cash equivalents, end of period	269,721	392,045	326,216
Supplemental cash flow information:
Interest paid	4,451	2,724	2,930
Taxes paid	8,237	9,636	48,349
Dividends declared, not paid	5,487	5,141	4,618
Noncash investing activity
Purchases of property and equipment included in accounts payable and accrued expenses	$ 16,847	$ 7,705	$ 5,136