Investment Securities - (Summary of Held-to-Maturity Securities, Unrealized Losses) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
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	46,725	$ 110,278
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,479)	(1,943)
Total Fair Value	109,856	110,278
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	(1,864)	(1,943)
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	35,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(25)	(72)
Total Fair Value	35,494	35,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	(230)	(72)
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	45,872	75,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,454)	(1,871)
Total Fair Value	74,362	75,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (1,634)	$ (1,871)