Investment Securities Held to Maturity Securities by Type (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	$ 154,035
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	851
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(49)
Securities held to maturity, fair value	154,837	$ 0
US Government Agencies Residential Mortgage-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	4,806
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	24
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0
Securities held to maturity, fair value	4,830
Residential Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	116,065
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	520
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(6)
Securities held to maturity, fair value	116,579
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	15,299
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	176
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0
Securities held to maturity, fair value	15,475
Obligations of States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	17,865
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	131
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(43)
Securities held to maturity, fair value	$ 17,953