Share-Based Compensation Arrangements (Share Options Activity) (Details) - Stock Options [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Number of Share Options:
Beginning of period	357,477
Granted	48,600	25,850	54,600
Exercised	(87,625)
Forfeited or expired	(9,336)
End of period	309,116	357,477
Options exercisable	189,791
Options expected to vest in future periods	119,325
Weighted Average Exercise Price (in dollars per share):
Beginning of period	$ 24.99
Granted	39.40
Exercised	25.55
Forfeited or expired	33.74
End of period	26.84	$ 24.99
Options exercisable	21.78
Options expected to vest in future periods	$ 34.89
Outstanding Weighted Average Remaining Contractual Term	6 years 5 days
Exercisable Weighted Average Remaining Contractual Term	4 years 4 months 2 days
Expected to Vest Weighted Average Remaining Contractual Term	8 years 8 months 2 days
Outstanding Aggregate Intrinsic Value	$ 3,921
Exercisable Aggregate Intrinsic Value	3,368
Expected to Vest Aggregate Intrinsic Value	$ 554