Investment Securities - Summary of Individual Securities in Continuous Unrealized Loss Position (Details)	3 Months Ended
	Mar. 31, 2019 USD ($) security	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($) security
Securities available-for-sale:
Less Than 12 Months, Fair Value	$ 13,464,000		$ 11,744,000
Less Than 12 Months, Gross Unrealized Losses	$ (88,000)		$ (42,000)
Less Than 12 Months, Number of Securities | security	8		9
12 months or Longer, Fair Value	$ 94,975,000		$ 96,611,000
12 months or Longer, Gross Unrealized Losses	$ (1,806,000)		$ (2,732,000)
12 months or Longer, Number of Securities | security	99		100
Total, Fair Value	$ 108,439,000		$ 108,355,000
Total, Gross Unrealized Losses	$ (1,894,000)		$ (2,774,000)
Total, Number of Securities | security	107		109
Securities held-to-maturity:
Less Than 12 Months, Fair Value	$ 4,170,000		$ 4,622,000
Less Than 12 Months, Gross Unrealized Losses	$ (9,000)		$ (61,000)
Less Than 12 Months, Number of Securities | security	2		9
12 Months or Longer, Fair Value	$ 13,931,000		$ 14,532,000
12 Months or Longer, Gross Unrealized Losses	$ (345,000)		$ (584,000)
12 Months or Longer, Number of Securities | security	17		18
Total, Fair Value	$ 18,101,000		$ 19,154,000
Total, Gross Unrealized Losses	$ (354,000)		$ (645,000)
Total, Number of Securities | security	19		27
OTTI, debt securities, including in earnings	$ 0	$ 0
Residential mortgage-backed securities
Securities available-for-sale:
Less Than 12 Months, Fair Value	0		$ 1,868,000
Less Than 12 Months, Gross Unrealized Losses	$ 0		$ (6,000)
Less Than 12 Months, Number of Securities | security	0		2
12 months or Longer, Fair Value	$ 38,935,000		$ 41,845,000
12 months or Longer, Gross Unrealized Losses	$ (713,000)		$ (1,225,000)
12 months or Longer, Number of Securities | security	45		48
Total, Fair Value	$ 38,935,000		$ 43,713,000
Total, Gross Unrealized Losses	$ (713,000)		$ (1,231,000)
Total, Number of Securities | security	45		50
Residential collateralized mortgage obligations
Securities available-for-sale:
Less Than 12 Months, Fair Value	$ 11,604,000		$ 7,067,000
Less Than 12 Months, Gross Unrealized Losses	$ (81,000)		$ (29,000)
Less Than 12 Months, Number of Securities | security	7		5
12 months or Longer, Fair Value	$ 36,076,000		$ 34,943,000
12 months or Longer, Gross Unrealized Losses	$ (722,000)		$ (1,002,000)
12 months or Longer, Number of Securities | security	35		34
Total, Fair Value	$ 47,680,000		$ 42,010,000
Total, Gross Unrealized Losses	$ (803,000)		$ (1,031,000)
Total, Number of Securities | security	42		39
Securities held-to-maturity:
Less Than 12 Months, Fair Value	$ 4,170,000		$ 2,022,000
Less Than 12 Months, Gross Unrealized Losses	$ (9,000)		$ (23,000)
Less Than 12 Months, Number of Securities | security	2		1
12 Months or Longer, Fair Value	$ 13,695,000		$ 14,035,000
12 Months or Longer, Gross Unrealized Losses	$ (344,000)		$ (579,000)
12 Months or Longer, Number of Securities | security	15		15
Total, Fair Value	$ 17,865,000		$ 16,057,000
Total, Gross Unrealized Losses	$ (353,000)		$ (602,000)
Total, Number of Securities | security	17		16
SBA loan pool securities
Securities available-for-sale:
Less Than 12 Months, Fair Value	$ 1,860,000		$ 2,809,000
Less Than 12 Months, Gross Unrealized Losses	$ (7,000)		$ (7,000)
Less Than 12 Months, Number of Securities | security	1		2
12 months or Longer, Fair Value	$ 19,964,000		$ 19,823,000
12 months or Longer, Gross Unrealized Losses	$ (371,000)		$ (505,000)
12 months or Longer, Number of Securities | security	19		18
Total, Fair Value	$ 21,824,000		$ 22,632,000
Total, Gross Unrealized Losses	$ (378,000)		$ (512,000)
Total, Number of Securities | security	20		20
Securities held-to-maturity:
Less Than 12 Months, Fair Value	$ 0		$ 2,600,000
Less Than 12 Months, Gross Unrealized Losses	$ 0		$ (38,000)
Less Than 12 Months, Number of Securities | security	0		8
12 Months or Longer, Fair Value	$ 236,000		$ 497,000
12 Months or Longer, Gross Unrealized Losses	$ (1,000)		$ (5,000)
12 Months or Longer, Number of Securities | security	2		3
Total, Fair Value	$ 236,000		$ 3,097,000
Total, Gross Unrealized Losses	$ (1,000)		$ (43,000)
Total, Number of Securities | security	2		11
Municipal bonds
Securities available-for-sale:
Less Than 12 Months, Fair Value	$ 0		$ 0
Less Than 12 Months, Gross Unrealized Losses	$ 0		$ 0
Less Than 12 Months, Number of Securities | security	0		0
12 months or Longer, Fair Value	$ 0		$ 0
12 months or Longer, Gross Unrealized Losses	$ 0		$ 0
12 months or Longer, Number of Securities | security	0		0
Total, Fair Value	$ 0		$ 0
Total, Gross Unrealized Losses	$ 0		$ 0
Total, Number of Securities | security	0		0