Debt - (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2015	Sep. 30, 2016	Oct. 02, 2015	Sep. 30, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Outstanding debt		$ 500,000		$ 500,000	$ 1,225,000
Maximum amount outstanding		4,600,000
Average amount borrowings		$ 2,000,000
Weighted-average interest rate		3.50%		3.50%
Debt covenants, Maximum leverage ratio				275.00%
Debt covenants, Minimum tangible net worth				$ 46,500,000
Debt covenants, Maximum capital expenditures				$ 5,000,000
Leverage ratio		0.05		0.05
Tangible net worth		$ 80,600,000		$ 80,600,000
Capital expenditures				$ 1,900,000
Unsecured Revolving Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 40,000,000
Line of credit facility, expiration date				2018-10
Life Insurance Loan Capacity [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 17,500,000
Line of Credit [Member]
Line of Credit Facility [Line Items]
Period borrowing			$ 10,000,000
Prime Rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.00%
Prime Rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.50%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.50%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.00%