UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - 3 months ended Mar. 31, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Shares of Common Stock (no par value)	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2017	49,328	49,328
Beginning balance at Dec. 31, 2017	$ 350,222		$ 44,787	$ 297,205	$ 8,230
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,829			4,829
Other comprehensive gain (loss), net of tax of $1.1 million	3,062				3,062
Other comprehensive income (loss), tax	1,100
Stock based compensation (in shares)		177
Stock based compensation	2,037		2,037
Stock options exercised (in shares)		15
Stock options exercised	104		104
Common stock issued (in shares)		0
Common stock issued	5		5
Shares retired for settlement of employee taxes upon issuance of vested equity awards (in shares)		(57)
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(1,858)		(1,858)
Common stock issued to acquire non-controlling interests of nTelos (in shares)		76
Common stock issued to acquire non-controlling interests of nTelos	$ 0		0
Ending balance (in shares) at Mar. 31, 2018	49,539	49,539
Ending balance at Mar. 31, 2018	$ 408,436		$ 45,075	352,069	$ 11,292
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in accounting principle - adoption of accounting standard (Note 2)	$ 50,035			$ 50,035