CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (unaudited) (USD $) In Thousands, except Share data	Total	Common Class A [Member]	Common Class B [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Opening Balance VALUE at Dec. 31, 2012	$ 269,494	$ 312	$ 72	$ 601,847	$ (332,737)	$ 0
Opening Balance SHARES at Dec. 31, 2012		31,226,047	7,197,532
Conversion of Class B common stock to Class A common stock SHARES		0	0
Compensation expense related to granting of stock options SHARES		0	0
Compensation expense related to granting of restricted stock units SHARES		96,560	0
Exercise of stock options SHARES		171,625	0
Purchase of vested employee restricted stock units SHARES		(186,038)	0
Net income (loss)	26,024	0	0	0	26,024
Conversion of Class B common stock to Class A common stock VALUE	0	0	0	0	0
Compensation expense related to granting of stock options VALUE	41	0	0	41	0
Compensation expense related to granting of restricted stock units VALUE	4,229	1	0	4,228	0
Purchase of vested employee restricted stock units	(1,640)	(2)	0	(1,638)	0
Forfeitures of dividend equivalents VALUE	0	0	0	0	0
Exercise of stock options VALUE	245	2	0	243
Ending Balance VALUE at Dec. 31, 2013	298,393	313	72	604,721	(306,713)	0
Ending Balance SHARES at Dec. 31, 2013		31,308,194	7,197,532
Conversion of Class B common stock to Class A common stock SHARES		0	0
Compensation expense related to granting of stock options SHARES	0
Compensation expense related to granting of restricted stock units SHARES		663,163
Exercise of stock options SHARES	15,750	15,750
Purchase of vested employee restricted stock units SHARES		(90,990)
Net income (loss)	1,363				1,363
Conversion of Class B common stock to Class A common stock VALUE	0	0	0
Compensation expense related to granting of stock options VALUE	3			3
Compensation expense related to granting of restricted stock units VALUE	1,205	7		1,198
Purchase of vested employee restricted stock units	(890)	(1)		(889)
Exercise of stock options VALUE	26	0		26
Ending Balance VALUE at Mar. 31, 2014	$ 300,100	$ 319	$ 72	$ 605,059	$ (305,350)	$ 0
Ending Balance SHARES at Mar. 31, 2014		31,896,117	7,197,532