Investments - Schedule of Unrealized Loss on Investments (Details) $ in Thousands	Mar. 31, 2017 USD ($) security	Dec. 31, 2016 USD ($) security
Less Than Twelve Months
Number of securities \| security	564	646
Gross unrealized losses	$ 3,569	$ 5,898
Fair value	$ 283,876	$ 344,434
Twelve Months or More
Number of securities \| security	36	25
Gross unrealized losses	$ 378	$ 236
Fair value	$ 11,047	$ 3,122
U.S. Government and Agency Securities
Less Than Twelve Months
Number of securities \| security	172	186
Gross unrealized losses	$ 1,535	$ 1,893
Fair value	$ 99,022	$ 111,216
Twelve Months or More
Number of securities \| security	11	0
Gross unrealized losses	$ 62	$ 0
Fair value	$ 3,085	$ 0
States, Municipalities and Political Subdivisions
Less Than Twelve Months
Number of securities \| security	122	201
Gross unrealized losses	$ 1,083	$ 2,551
Fair value	$ 91,937	$ 136,360
Twelve Months or More
Number of securities \| security	4	0
Gross unrealized losses	$ 81	$ 0
Fair value	$ 5,180	$ 0
Public Utilities
Less Than Twelve Months
Number of securities \| security	20	8
Gross unrealized losses	$ 68	$ 73
Fair value	$ 6,230	$ 2,222
Twelve Months or More
Number of securities \| security	0	0
Gross unrealized losses	$ 0	$ 0
Fair value	$ 0	$ 0
Corporate Securities
Less Than Twelve Months
Number of securities \| security	236	215
Gross unrealized losses	$ 813	$ 1,100
Fair value	$ 84,342	$ 88,605
Twelve Months or More
Number of securities \| security	1	1
Gross unrealized losses	$ 21	$ 26
Fair value	$ 1,024	$ 1,021
Redeemable Preferred Stocks
Less Than Twelve Months
Number of securities \| security	0	7
Gross unrealized losses	$ 0	$ 62
Fair value	$ 0	$ 764
Twelve Months or More
Number of securities \| security	3	0
Gross unrealized losses	$ 52	$ 0
Fair value	$ 307	$ 0
Fixed Maturities
Less Than Twelve Months
Number of securities \| security	550	617
Gross unrealized losses	$ 3,499	$ 5,679
Fair value	$ 281,531	$ 339,167
Twelve Months or More
Number of securities \| security	19	1
Gross unrealized losses	$ 216	$ 26
Fair value	$ 9,596	$ 1,021
Common Stock
Less Than Twelve Months
Number of securities \| security	7	16
Gross unrealized losses	$ 26	$ 140
Fair value	$ 530	$ 2,450
Twelve Months or More
Number of securities \| security	11	17
Gross unrealized losses	$ 129	$ 179
Fair value	$ 967	$ 1,732
Nonredeemable Preferred Stocks
Less Than Twelve Months
Number of securities \| security	6	12
Gross unrealized losses	$ 24	$ 52
Fair value	$ 854	$ 1,830
Twelve Months or More
Number of securities \| security	6	7
Gross unrealized losses	$ 33	$ 31
Fair value	$ 484	$ 369
Equity Securities
Less Than Twelve Months
Number of securities \| security	13	28
Gross unrealized losses	$ 50	$ 192
Fair value	$ 1,384	$ 4,280
Twelve Months or More
Number of securities \| security	17	24
Gross unrealized losses	$ 162	$ 210
Fair value	$ 1,451	$ 2,101
Other Long-term Investments
Less Than Twelve Months
Number of securities \| security	1	1
Gross unrealized losses	$ 20	$ 27
Fair value	$ 961	$ 987
Twelve Months or More
Number of securities \| security	0	0
Gross unrealized losses	$ 0	$ 0
Fair value	$ 0	$ 0

Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months [Abstract]

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Available For Sale Securities Continuous Unrealized Loss Position Twelve Months or More [Abstract]

+ References

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- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.

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This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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Number of investment positions in available-for-sale investments in a continuous unrealized loss position for less than one year or normal operating cycle, if longer, for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

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Number of investment positions in available-for-sale investments that have been in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

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