Investment Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Available-for-sale Securities [Abstract]
Amortized Cost	$ 374,740	$ 398,815	[1]
Gross Unrealized Gains	3,740	920
Gross Unrealized Losses	834	9,301
Total	377,646	390,434	[1]
Held-to-maturity Securities [Abstract]
Amortized Cost	139,813	147,967
Gross Unrealized Gains	2,417	0
Gross Unrealized Losses	13	2,782
Total	142,217	145,185	[1]
Amortized Cost, Total	514,553	546,782
Gross Unrealized Gains, Total	6,157	920
Gross Unrealized Losses, Total	847	12,083
Estimated Fair Value, Total	519,863	535,619
U.S. Government-sponsored agencies [Member]
Available-for-sale Securities [Abstract]
Amortized Cost		2,005
Gross Unrealized Gains		3
Gross Unrealized Losses		0
Total		2,008
Residential mortgage-backed securities - GSE [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	269,169	286,057
Gross Unrealized Gains	2,497	339
Gross Unrealized Losses	671	8,289
Total	270,995	278,107
Held-to-maturity Securities [Abstract]
Amortized Cost	115,395	120,197
Gross Unrealized Gains	1,975	0
Gross Unrealized Losses	13	2,310
Total	117,357	117,887
Residential mortgage-backed securities - Private [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	28,567	33,235
Gross Unrealized Gains	450	578
Gross Unrealized Losses	33	236
Total	28,984	33,577
Held-to-maturity Securities [Abstract]
Amortized Cost	14,363	17,712
Gross Unrealized Gains	38	0
Gross Unrealized Losses	0	298
Total	14,401	17,414
Commercial mortgage-backed securities - GSE [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	21,779	21,980
Gross Unrealized Gains	388	0
Gross Unrealized Losses	0	368
Total	22,167	21,612
Commercial mortgage-backed securities - Private [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	17,847	17,869
Gross Unrealized Gains	362	0
Gross Unrealized Losses	128	294
Total	18,081	17,575
Held-to-maturity Securities [Abstract]
Amortized Cost	10,055	10,058
Gross Unrealized Gains	404	0
Gross Unrealized Losses	0	174
Total	10,459	9,884
Corporate notes [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	37,378	37,669
Gross Unrealized Gains	43	0
Gross Unrealized Losses	2	114
Total	$ 37,419	$ 37,555

[1] Derived from audited consolidated financial statements