Investment Securities (State And Municipal Obligations, By State And Economic Sector) (Details) - Jun. 30, 2015 - yr	Total
Sector Classification, Texas [Member]
Investment [Line Items]
% of Portfolio	12.60%
Average Life (in years)	5.8
Average Rating (Moody's)	Aa2
Sector Classification, Florida [Member]
Investment [Line Items]
% of Portfolio	7.70%
Average Life (in years)	4.0
Average Rating (Moody's)	Aa3
Sector Classification Ohio [Member]
Investment [Line Items]
% of Portfolio	6.50%
Average Life (in years)	5.7
Average Rating (Moody's)	Aa2
Sector Classification New York [Member]
Investment [Line Items]
% of Portfolio	6.20%
Average Life (in years)	6.4
Average Rating (Moody's)	Aa2
Sector Classification, Washington [Member]
Investment [Line Items]
% of Portfolio	5.30%
Average Life (in years)	5.1
Average Rating (Moody's)	Aa2
Sector Classification, General Obligation [Member]
Investment [Line Items]
% of Portfolio	34.70%
Average Life (in years)	5.6
Average Rating (Moody's)	Aa2
Sector Classification, Lease [Member]
Investment [Line Items]
% of Portfolio	19.10%
Average Life (in years)	5.6
Average Rating (Moody's)	Aa3
Sector Classification, Housing [Member]
Investment [Line Items]
% of Portfolio	12.50%
Average Life (in years)	3.8
Average Rating (Moody's)	Aa1
Sector Classification, Transportation [Member]
Investment [Line Items]
% of Portfolio	12.10%
Average Life (in years)	4.8
Average Rating (Moody's)	A1
Sector Classification, Limited Tax [Member]
Investment [Line Items]
% of Portfolio	8.40%
Average Life (in years)	6.6
Average Rating (Moody's)	Aa2