Accounting Pronouncements Recently Issued Narrative - Impact of implementation of new accounting standards (Details) - Accounting Standards Update 2016-09 [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Cumulative Effect of New Accounting Principle in Period of Adoption			$ 67
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	$ 22	$ 1,300
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Diluted Earnings Per Share		$ 0.02
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			(117)
Common Stock [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ 184