Long-Term Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Long-term debt	$ 0.0	$ 0.0
Restricted cash and investments	1.1	$ 3.6
BB&T Bank [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Principal amount of the line of credit	$ 7.5
Expiration date of credit agreement	Feb. 17, 2017
BB&T Bank [Member] | Revolving Credit Facility [Member] | Wall Street Journal Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate	4.50%
Citizen's Bank [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Principal amount of the line of credit	$ 5.0
Line of Credit Facility, Expiration Period	3 years
Percentage of letter of credit fees per annum	1.25%
Citizen's Bank [Member] | Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate	2.25%