Regulatory Capital (Narrative) (Details)	Mar. 31, 2019	Jan. 01, 2019
Common equity Tier 1 capital to risk-weighted assets minimum ratio	4.50%
Total Capital to risk-weighted assets	8.00%
Tier 1 leverage ratio	4.00%
Capital conversion buffer percentage		2.50%
Minimum
Minimum ratio of Tier 1 capital to risk-weighted assets	4.00%
Maximum
Minimum ratio of Tier 1 capital to risk-weighted assets	6.00%
Conservation Buffer Rule Starting January 2016 [Member]
Capital conversion buffer percentage	0.625%
Conservation Buffer Rule Subsequent to 2016 [Member]
Capital conversion buffer percentage	0.625%