Condensed Consolidated Statements of Changes in Stockholders' Equity - 3 months ended Mar. 31, 2018 - USD ($) shares in Thousands, $ in Thousands	Common Stock Common Class A	Common Stock Common Class B	Additional Paid-In Capital	Treasury Stock Common Class A	Retained Earnings	Accumulated Other Comprehensive Loss	Total
Balance at the beginning of the period at Dec. 31, 2017	$ 3	$ 2	$ 265,329	$ (57,303)	$ 30,401	$ 472	$ 238,904
Balance at the beginning of the period (in shares) at Dec. 31, 2017	25,171	20,801
Condensed Consolidated Statements of Changes in Stockholders' Equity
Net loss					(7,559)		(7,559)
Stock-based compensation			996				996
Repurchase of Class A common stock				(34)			(34)
Exercise of warrants	$ 0		20				20
Exercise of warrants (in shares)	2
Other comprehensive income, net of tax						1,150	1,150
Balance at the end of the period at Mar. 31, 2018	$ 3	$ 2	$ 266,345	$ (57,337)	$ 22,842	$ 1,622	$ 233,477
Balance at the end of the period (in shares) at Mar. 31, 2018	25,173	20,801