Reserves for Unpaid Losses and Loss Adjustment Expenses (Incurred and Paid Claims Development - Personal Segment) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) claim	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)	Dec. 31, 2007 USD ($)
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	$ 7,608	$ (6,953)	$ (5,203)
Incurred claims and claim adjustment expenses related to current year	246,080	237,102	215,258
Total incurred	253,688	230,149	210,055
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	150,378	122,122	123,100
Paid claims and allocated claim adjustment expenses related to current year	93,067	83,132	76,231
Total paid	243,445	205,254	199,331
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	358,330	348,087	323,192	$ 312,468
Personal Segment [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total incurred	490,765
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Total paid	475,230
All outstanding liabilities before 2007, net of reinsurance	9
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	15,544
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2007 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	$ 32,528	32,528	32,517	32,272	$ 31,931	$ 31,651	$ 31,485	$ 31,252	$ 31,603	$ 28,774
Cumulative number of reported claims | claim	15,814
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 32,530	32,531	31,213	32,056	31,523	31,355	30,975	30,043	27,757	$ 18,106
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2008 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	$ 40,369	40,324	40,239	40,170	39,793	39,412	38,329	36,976	36,247
Cumulative number of reported claims | claim	17,353
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 40,347	40,323	40,309	40,210	39,511	38,925	36,782	32,555	$ 20,005
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2009 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	$ 49,891	49,772	49,694	48,930	47,977	46,244	42,092	40,436
Cumulative number of reported claims | claim	21,052
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 49,853	49,704	49,539	49,287	47,967	44,689	37,621	$ 23,306
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2010 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	84,591	84,252	83,903	84,724	80,765	78,294	63,862
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 6
Cumulative number of reported claims | claim	30,179
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 84,556	84,111	83,511	82,624	75,199	67,755	$ 38,643
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2011 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	86,948	86,804	86,757	87,810	77,652	75,746
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ (28)
Cumulative number of reported claims | claim	31,612
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 86,593	86,217	85,533	83,497	67,939	$ 46,416
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2012 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	72,042	71,513	70,552	73,795	58,604
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 50
Cumulative number of reported claims | claim	23,937
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 71,995	70,807	68,849	64,278	$ 37,860
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2013 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	60,211	60,100	59,132	55,706
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 234
Cumulative number of reported claims | claim	23,461
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 59,775	58,047	54,514	$ 45,901
Personal Segment [Member] | Loss Adjustment Expenses Recognized In 2014 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	6,243	5,340	5,452
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 406
Cumulative number of reported claims | claim	19,275
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 5,631	4,418	$ 2,515
Personal Segment [Member] | Loss Adjustment Expenses Recognized in 2015 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to prior years	25,682	23,104
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,813
Cumulative number of reported claims | claim	23,234
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 22,281	$ 11,570
Personal Segment [Member] | Loss Adjustment Expenses Recognized in 2016 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to current year	32,260
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 6,638
Cumulative number of reported claims | claim	21,134
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to current year	$ 21,669