Share-Based Compensation (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Share-Based Compensation [Abstract]
Options maximum term period	10 years	10 years
Shares [Roll Forward]
Options outstanding, beginning of period (in shares)	60,605
Granted (in shares)	0
Exercised (in shares)	(48,287)
Canceled or expired (in shares)	(1,250)
Options outstanding, end of period (in shares)	11,068
Options exercisable, end of period (in shares)	11,068
Weighted Average Exercise Price [Roll Forward]
Options outstanding, beginning of period (in dollars per share)	$ 20.05
Granted (in dollars per share)	0
Exercised (in dollars per share)	20.05
Canceled or expired (in dollars per share)	20.05
Options outstanding, end of period (in dollars per share)	20.05
Options exercisable, end of period (in dollars per share)	$ 20.05
Weighted Average Remaining Contractual Life (in years) [Abstract]
Options outstanding, end of period	14 days
Options exercisable, end of period	14 days
Aggregate Intrinsic Value [Abstract]
Options outstanding, end of period	$ 137,000
Options exercisable, end of period	137,000
Proceeds from exercise of stock options	968,000	$ 0
Unrecognized compensation expense related to nonvested options	$ 0	$ 0
Common Stock, Capital Shares Reserved for Future Issuance	246,478	0
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	5.00%	0.00%
Stock Issued During Period, Shares, Employee Stock Purchase Plans	2,523	0