Summary of Significant Accounting Policies Cost of Customer Relationships Acquired (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Number of years of available premiums	50 years
Total	$ 17,499	$ 19,415	$ 21,585	$ 23,542
Acquisition	0	0	0
Amortization	(2,129)	(2,063)	(2,317)
Change in effects of unrealized (gains) losses on CCRA	$ 213	$ (107)	$ 360
Number of Years-Cost of Customer Relationship Acquired Amortization	5 years
2018	$ 1,619
2019	1,424
2020	1,289
2021	1,168
2022	1,060
Thereafter	11,285
Net	17,845
Effects of unrealized (gains) losses on CCRA	$ (346)
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Annuity Credit Rate Associated with Amortization Method of Present Value of Future Insurance Profits	2.50%
Interest Accrual Rate Associated with Amortization Method of Present Value of Future Insurance Profits	2.50%
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Annuity Credit Rate Associated with Amortization Method of Present Value of Future Insurance Profits	5.50%
Interest Accrual Rate Associated with Amortization Method of Present Value of Future Insurance Profits	6.00%
Customer Relationships [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	3.70%
Customer Relationships [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	8.50%