Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity and Stock Based Compensation - Nonvested (Details)

v3.7.0.1
Stockholders' Equity and Stock Based Compensation - Nonvested (Details) - Restricted stock - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Shares              
Nonvested shares at the beginning of the period 186,081            
Granted (in shares) 78,576   171,252 44,000 98,689 56,500 92,000
Vested (in shares) (23,051)            
Forfeited (in shares)     (7,167) (4,465) (34,487) (775) (3,525)
Nonvested shares at the end of the period 241,606   186,081        
Weighted Average Grant Date Fair Value              
Nonvested shares at the beginning of period (in dollars per share) $ 15.58            
Granted (in dollars per share) 18.19            
Vested (in dollars per share) 15.08            
Nonvested shares at the end of period (in dollars per share) $ 15.81   $ 15.58        
Unrecognized compensation cost (in dollars) $ 3.8            
Weighted average period for recognition of unrecognized compensation cost 3 years 4 months 24 days            
General and Administrative Expense              
Weighted Average Grant Date Fair Value              
Share-based compensation cost $ 0.3 $ 0.4