Securities, Summary of Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2015 USD ($) Security Securities	Dec. 31, 2014 USD ($) Security
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	179	45
Less than 12 months, fair value	$ 187,173	$ 83,378
Less than 12 months, gross unrealized losses	$ (2,718)	$ (255)
12 months or more, number of securities | Security	38	116
12 months or more, fair value	$ 52,682	$ 247,879
12 months or more, gross unrealized losses	$ (1,926)	$ (4,906)
Total, number of securities | Security	217	161
Total, fair value	$ 239,855	$ 331,257
Total, gross unrealized losses	$ (4,644)	$ (5,161)
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of securities | Security	55	8
Less than 12 months, fair value	$ 134,728	$ 17,001
Less than 12 months, gross unrealized losses	$ (1,296)	$ (20)
12 months or more, number of securities | Security	7	31
12 months or more, fair value	$ 23,852	$ 106,951
12 months or more, gross unrealized losses	$ (317)	$ (2,144)
Total, number of securities | Security	62	39
Total, fair value	$ 158,580	$ 123,952
Total, gross unrealized losses	$ (1,613)	$ (2,164)
Securities Disclosures [Abstract]
Number of debt securities with unrealized losses | Securities	279
Debt securities with unrealized losses as percentage of total individual securities' amortized cost basis	1.50%
Debt securities with unrealized losses as percentage of amortized cost basis of investment securities portfolio	1.10%
Number of debt securities in continuous loss position for over 12 months | Securities	45
Debt securities in a continuous loss position for over 12 months, amortized cost basis	$ 78,800
Debt securities in a continuous loss position for over 12 months, unrealized loss	$ 2,200
US Treasuries [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	2	4
Less than 12 months, fair value	$ 9,999	$ 24,000
Less than 12 months, gross unrealized losses	$ 0	$ 0
12 months or more, number of securities | Security	0	0
12 months or more, fair value	$ 0	$ 0
12 months or more, gross unrealized losses	$ 0	$ 0
Total, number of securities | Security	2	4
Total, fair value	$ 9,999	$ 24,000
Total, gross unrealized losses	$ 0	$ 0
US Government Agencies [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	49	4
Less than 12 months, fair value	$ 116,473	$ 43,983
Less than 12 months, gross unrealized losses	$ (921)	$ (17)
12 months or more, number of securities | Security	11	66
12 months or more, fair value	$ 47,338	$ 232,482
12 months or more, gross unrealized losses	$ (632)	$ (4,138)
Total, number of securities | Security	60	70
Total, fair value	$ 163,811	$ 276,465
Total, gross unrealized losses	$ (1,553)	$ (4,155)
Corporate Debt Securities [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	112	37
Less than 12 months, fair value	$ 31,414	$ 15,395
Less than 12 months, gross unrealized losses	$ (1,509)	$ (238)
12 months or more, number of securities | Security	27	50
12 months or more, fair value	$ 5,344	$ 15,397
12 months or more, gross unrealized losses	$ (1,294)	$ (768)
Total, number of securities | Security	139	87
Total, fair value	$ 36,758	$ 30,792
Total, gross unrealized losses	$ (2,803)	$ (1,006)
Mutual Funds or Other Equity Securities [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	0	0
Less than 12 months, fair value	$ 0	$ 0
Less than 12 months, gross unrealized losses	$ 0	$ 0
12 months or more, number of securities | Security	0	0
12 months or more, fair value	$ 0	$ 0
12 months or more, gross unrealized losses	$ 0	$ 0
Total, number of securities | Security	0	0
Total, fair value	$ 0	$ 0
Total, gross unrealized losses	$ 0	$ 0
Municipal Bonds [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	2	0
Less than 12 months, fair value	$ 679	$ 0
Less than 12 months, gross unrealized losses	$ (5)	$ 0
12 months or more, number of securities | Security	0	0
12 months or more, fair value	$ 0	$ 0
12 months or more, gross unrealized losses	$ 0	$ 0
Total, number of securities | Security	2	0
Total, fair value	$ 679	$ 0
Total, gross unrealized losses	$ (5)	$ 0
Mortgage-backed Securities [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	14
Less than 12 months, fair value	$ 28,608
Less than 12 months, gross unrealized losses	$ (283)
12 months or more, number of securities | Security	0
12 months or more, fair value	$ 0
12 months or more, gross unrealized losses	$ 0
Total, number of securities | Security	14
Total, fair value	$ 28,608
Total, gross unrealized losses	$ (283)
US Government Agencies [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of securities | Security	16	1
Less than 12 months, fair value	$ 51,865	$ 4,993
Less than 12 months, gross unrealized losses	$ (404)	$ (7)
12 months or more, number of securities | Security	7	19
12 months or more, fair value	$ 23,852	$ 77,536
12 months or more, gross unrealized losses	$ (317)	$ (1,943)
Total, number of securities | Security	23	20
Total, fair value	$ 75,717	$ 82,529
Total, gross unrealized losses	$ (721)	$ (1,950)
Mortgage-backed Securities [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of securities | Security	39	7
Less than 12 months, fair value	$ 82,863	$ 12,008
Less than 12 months, gross unrealized losses	$ (892)	$ (13)
12 months or more, number of securities | Security	0	12
12 months or more, fair value	$ 0	$ 29,415
12 months or more, gross unrealized losses	$ 0	$ (201)
Total, number of securities | Security	39	19
Total, fair value	$ 82,863	$ 41,423
Total, gross unrealized losses	$ (892)	$ (214)