Common Stock-Schedule of (Loss) Earnings Per Share, Diluted (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Class A Common Stock      
Numerator:      
Allocation of undistributed (loss) earnings $ (32,651) $ 10,522 $ 23,407
Dividends paid 8,573 7,273 5,384
Net (loss) income available to common shareholders, diluted $ (24,078) $ 17,795 $ 28,791
Denominator:      
Weighted-average common shares outstanding, basic (in shares) 30,596 30,237 29,853
Weighted Average Number Diluted Shares Outstanding Adjustment 0 746 [1] 1,002 [1]
Weighted-average number of shares outstanding, diluted 30,596 30,983 30,855
(Loss) Earnings Per Share - Diluted (usd per share) $ (0.79) $ 0.57 $ 0.93
Class B Common Stock      
Numerator:      
Allocation of undistributed (loss) earnings $ (26,348) $ 8,385 $ 18,731
Dividends paid 4,938 4,444 3,456
Net (loss) income available to common shareholders, diluted $ (21,410) $ 12,829 $ 22,187
Denominator:      
Weighted-average common shares outstanding, basic (in shares) 24,690 24,690 24,690
Weighted Average Number Diluted Shares Outstanding Adjustment 0 0 0
Weighted-average number of shares outstanding, diluted 24,690 24,690 24,690
(Loss) Earnings Per Share - Diluted (usd per share) $ (0.87) $ 0.52 $ 0.90
[1] (1) For the year ended December 31, 2015, the Company excluded from its loss per share calculations all common share equivalents because their inclusion would have been anti-dilutive. The weighted-average number of these common share equivalents for the year ended December 31, 2015 totaled approximately 494,000.