CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Service revenue	$ 149,175	$ 146,777
Operating expenses:
Network operations (including $144 and $2,076 of equity-based compensation expense, respectively, exclusive of depreciation and amortization shown separately below)	57,449	57,092
Selling, general, and administrative (including $5,912 and $5,231 of equity-based compensation expense, respectively)	40,627	41,442
Depreciation and amortization	22,688	21,970
Total operating expenses	120,764	120,504
Gains on equipment transactions		18
Gains on lease terminations	373
Operating income	28,784	26,291
Interest expense	(35,439)	(15,836)
Unrealized foreign exchange gain on 2024 Euro Notes	8,014	18,870
Loss on debt extinguishment and repurchase - 2022 Notes		(3,868)
Interest income and other, net	319	744
Income before income taxes	1,678	26,201
Income tax expense	(541)	(7,350)
Net income	1,137	18,851
Comprehensive (loss) income:
Net income	1,137	18,851
Foreign currency translation adjustment	(2,165)	(5,210)
Comprehensive (loss) income	$ (1,028)	$ 13,641
Net income per common share:
Basic net income per common share	$ 0.02	$ 0.41
Diluted net income per common share	0.02	0.41
Dividends declared per common share	$ 0.855	$ 0.755
Weighted-average common shares - basic (in shares)	46,575,848	46,067,096
Weighted-average common shares - diluted (in shares)	46,929,191	46,507,258