Net Income (Loss) per Share of Common Stock (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Numerators for earnings per share:
Net income (loss) that is available to common shareholders	$ (25,168)	$ 12,436	$ (28,552)	$ 14,425
Denominator for basic earnings per share:
Weighted average shares outstanding	21,672,844	21,288,897	21,600,125	21,202,411
Denominator for diluted earnings per share:
Effect of stock options and restricted stock units	0	654,388	0	504,622
Adjusted weighted average shares and assumed conversions	21,672,844	21,943,285	21,600,125	21,707,033
Basic earnings (loss) per share	$ (1.16)	$ 0.58	$ (1.32)	$ 0.68
Diluted earnings (loss) per share	$ (1.16)	$ 0.57	$ (1.32)	$ 0.66
Net loss position (excluded from denominator)
Shares excluded from diluted earnings (loss) per share due to:
Antidilutive securities excluded from diluted earnings per share	490,706	0	465,577	0
Inclusion would have been anti-dilutive (excluded from calculation)
Shares excluded from diluted earnings (loss) per share due to:
Antidilutive securities excluded from diluted earnings per share	182,850	319,288	130,165	370,936