Earnings (Loss) Per Share - Narrative (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of common stock warrant and common stock options exercised (in shares)	208,000	0	540,000	1,646,372
Number of common stock issued for stock warrant and stock options exercised (in shares)	208,000		353,677	1,373,515
Shares surrendered in lieu of cash payment (in shares)	0		186,323	272,857
Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive potential shares (in shares)	292,123		179,613