UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - 6 months ended Jun. 30, 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)	12,653			12,653
Other comprehensive gain (loss), net of tax of $1.4 million	3,895				3,895
Other comprehensive gain (loss), tax	1,400
Stock based compensation (in shares)		205
Stock based compensation	3,407		3,407
Stock options exercised (in shares)		15
Stock options exercised	104		104
Common stock issued	10		10
Shares retired for settlement of employee taxes upon issuance of vested equity awards (in shares)		(66)
Shares retired for settlement of employee taxes upon issuance of vested equity awards	(2,136)		(2,136)
Common stock issued to acquire non-controlling interests of nTelos (in shares)		76
Common stock issued to acquire non-controlling interest in nTelos	$ 0
Ending balance (in shares) at Jun. 30, 2018	49,558	49,558
Ending balance at Jun. 30, 2018	$ 418,190		$ 46,172	359,893	$ 12,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in accounting principle - adoption of accounting standard (Note 2)	$ 50,035			$ 50,035