Stock-Based Compensation Plans (Schedule of Compensation Expense Recognized in Connection with LTIP) (Details) - Long-Term Performance Share Plan [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense(1)	[1]	$ 1,080	$ 330	$ 151
Related income tax benefit		378	116	53
Fair value of grants vested		$ 725	$ 412	$ 0

[1] (1)For the year ended December 31, 2016, $84,000 of compensation expense associated with the LTIP for the plan year January 1, 2016 to December 31, 2018 was accounted for within total compensation expense for restricted stock and restricted stock units above as this plan contains both performance- and service-based conditions.