CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2014	$ 258,346		$ 29,712	$ 227,512	$ 1,122
Balance (in shares) at Dec. 31, 2014		48,265
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	40,864			40,864
Other comprehensive income (loss), net of tax	(707)				(707)
Dividends declared	(11,629)			(11,629)
Dividends reinvested in common stock	544		544
Dividends reinvested in common stock (in shares)		22
Stock based compensation	2,719		2,719
Common stock issued through exercise of incentive stock options	996		996
Common stock issued through exercise of incentive stock options (in shares)		87
Common stock issued for share awards (in shares)		212
Common stock issued	11		11
Common stock issued (in shares)		1
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(1,885)		(1,885)
Common stock withheld for taxes (in shares)		(111)
Net excess tax benefit from stock options exercised	679		679
Balance at Dec. 31, 2015	289,938		32,776	256,747	415
Balance (in shares) at Dec. 31, 2015		48,475
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(895)			(895)
Other comprehensive income (loss), net of tax	6,373				6,373
Dividends declared	(12,228)			(12,228)
Dividends reinvested in common stock	524		524
Dividends reinvested in common stock (in shares)		19
Stock based compensation	3,506		3,506
Common stock issued through exercise of incentive stock options	3,359		3,359
Common stock issued through exercise of incentive stock options (in shares)		371
Common stock issued for share awards (in shares)		190
Common stock issued	14		14
Common stock issued (in shares)		2
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(5,097)		(5,097)
Common stock withheld for taxes (in shares)		(198)
Common stock issued to acquire non-controlling interests of nTelos	10,400		10,400
Common stock issued to acquire a non-controlling interests of nTelos (in shares)		76
Balance at Dec. 31, 2016	$ 295,894		45,482	243,624	6,788
Balance (in shares) at Dec. 31, 2016	48,935	48,935
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 66,390			66,390
Other comprehensive income (loss), net of tax	1,442				1,442
Dividends declared	(12,809)			(12,809)
Dividends reinvested in common stock	552		552	0
Dividends reinvested in common stock (in shares)		15
Stock based compensation	4,184		4,184
Common stock issued through exercise of incentive stock options	2,394		2,394
Common stock issued through exercise of incentive stock options (in shares)		363
Common stock issued for share awards (in shares)		(216)
Common stock issued	21		21
Common stock issued (in shares)		1
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(7,846)		(7,846)
Common stock issued to acquire non-controlling interests of nTelos	0		0
Common stock issued to acquire a non-controlling interests of nTelos (in shares)		76
Balance at Dec. 31, 2017	$ 350,222		$ 44,787	$ 297,205	$ 8,230
Balance (in shares) at Dec. 31, 2017	49,328	49,328