Investment Securities - (Summary of Held-to-Maturity Securities, Unrealized Losses) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Fair Value, Less than 12 months		$ 63,131
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(385)
Fair Value, 12 months or more	$ 36,935	46,725
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(319)	(1,479)
Total Fair Value	36,935	109,856
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	(319)	(1,864)
Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair Value, Less than 12 months		34,641
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(205)
Fair Value, 12 months or more		853
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(25)
Total Fair Value		35,494
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		(230)
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair Value, Less than 12 months		28,490
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(180)
Fair Value, 12 months or more	36,935	45,872
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(319)	(1,454)
Total Fair Value	36,935	74,362
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (319)	$ (1,634)