Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Details)

v3.19.1
Stock Based Compensation (Details) - Employee Stock Option [Member] - $ / shares
 3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Shares - Nonvested, Beginning Balance (in shares) 27,423 30,690
Shares - Granted (in shares) 7,407 4,433
Shares - Vested (in shares) (3,302) (7,700)
Shares - Forfeited (in shares) 0 0
Shares - Nonvested, Ending Balance (in shares) 31,528 27,423
Weighted-Average Grant Date Fair Value - Nonvested, Beginning Balance (in dollars per share) $ 32.58 $ 28.51
Weighted-Average Grant Date Fair Value - Granted (in dollars per share) 43.00 43.50
Weighted-Average Grant Date Fair Value - Vested (in dollars per share) 27.26 22.64
Weighted-Average Grant Date Fair Value - Forfeited (in dollars per share) 0 0
Weighted-Average Grant Date Fair Value - Nonvested, Ending Balance (in dollars per share) $ 35.58 $ 32.58