CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Shares of Common Stock (no par value)	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance (in shares) at Dec. 31, 2016		48,935,000
Balance at Dec. 31, 2016	$ 295,894		$ 45,482	$ 243,624	$ 6,788
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	66,390			66,390
Other comprehensive gain (loss), net of tax	1,442				1,442
Dividends declared	(12,809)			(12,809)
Dividends reinvested in common stock (in shares)		15,000
Dividends reinvested in common stock	552		552
Stock based compensation (in shares)		154,000
Stock based compensation	4,184		4,184
Stock options exercised (in shares)		363,000
Stock options exercised	2,394		2,394
Common stock issued (in shares)		1,000
Common stock issued	21		21
Shares retired for settlement of employee taxes upon issuance of vested equity awards (in shares)		(216,000)
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(7,846)		(7,846)
Common stock issued to acquire a non-controlling interests of nTelos (in shares)		76,000
Common stock issued to acquire non-controlling interest in nTelos	0
Balance (in shares) at Dec. 31, 2017		49,328,000
Balance at Dec. 31, 2017	350,222		44,787	297,205	8,230
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	46,595			46,595
Other comprehensive gain (loss), net of tax	50				50
Dividends declared	(13,386)			(13,386)
Dividends reinvested in common stock (in shares)		11,000
Dividends reinvested in common stock	520		520
Stock based compensation (in shares)		206,000
Stock based compensation	5,367		5,367
Stock options exercised (in shares)		113,000
Stock options exercised	787		787
Common stock issued (in shares)		1,000
Common stock issued	26		26
Shares retired for settlement of employee taxes upon issuance of vested equity awards (in shares)		(105,000)
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(4,031)		(4,031)
Common stock issued to acquire a non-controlling interests of nTelos (in shares)		76,000
Common stock issued to acquire non-controlling interest in nTelos	$ 0
Balance (in shares) at Dec. 31, 2018	49,630,000	49,630,000
Balance at Dec. 31, 2018	$ 442,247		47,456	386,511	8,280
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	54,935			54,935
Other comprehensive gain (loss), net of tax	(7,972)				(7,972)
Dividends declared	(14,442)			(14,442)
Dividends reinvested in common stock (in shares)		14,000
Dividends reinvested in common stock	499		499
Share repurchases (in shares)		(200,000)
Share repurchases	(7,231)	$ (7,231)
Stock based compensation (in shares)		184,000
Stock based compensation	4,182		4,182
Stock options exercised (in shares)		29,000
Stock options exercised	81		81
Common stock issued	34		34
Shares retired for settlement of employee taxes upon issuance of vested equity awards (in shares)		(62,000)
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(2,911)		(2,911)
Common stock issued to acquire a non-controlling interests of nTelos (in shares)		76,000
Common stock issued to acquire non-controlling interest in nTelos	$ 0
Balance (in shares) at Dec. 31, 2019	49,671,000	49,671,000
Balance at Dec. 31, 2019	$ 469,422		$ 42,110	$ 427,004	$ 308