Debt (Details)						1 Months Ended	3 Months Ended		12 Months Ended
	Feb. 27, 2017 USD ($)	Oct. 31, 2016 USD ($)	Dec. 23, 2014 USD ($) covenant	Jan. 17, 2014 USD ($)	Jan. 19, 2010 USD ($)	Dec. 31, 2013 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2013	Jan. 01, 2019 USD ($)	Dec. 22, 2017 USD ($)	May 04, 2017 USD ($)	May 03, 2017 USD ($)	Dec. 31, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Proceeds from term loan							$ 10,000,000	$ 0
SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Credit facility, term					4 years
Revolving credit facility, unused capacity, commitment fee percentage									0.50%
Line of Credit [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity of credit facility							$ 20,000,000
Debt instrument, variable interest rate, term							1 month
Applicable margin (percent)					1.75%
Revolving credit facility, unused capacity, commitment fee percentage					0.25%
Interest rate during period							2.53%
Sun Trust Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Proceeds from term loan	$ 10,000,000	$ 3,600,000
Amount of line of credit outstanding							$ 13,600,000
Sun Trust Revolving Credit Facility [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity of credit facility			$ 20,000,000.0	$ 25,000,000	$ 15,000,000.0						$ 25,000,000
Debt instrument, variable interest rate, term			1 month
Revolving credit facility, unused capacity, commitment fee percentage			0.25%	0.50%
Long-term debt, percentage bearing fixed interest, percentage rate				1.75%
Number of debt covenants | covenant			2
Debt instrument, term of debt covenants to apply			30 days
Sun Trust Term Loan [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, face amount					15,000,000.0
Debt instrument, periodic payment, principal					$ 800,000
Debt instrument, financial principal payment						$ 3,000,000
Long-term debt, weighted average interest rate														0.25%	25000.00%
London Interbank Offered Rate (LIBOR) [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, variable interest rate, term									1 month
London Interbank Offered Rate (LIBOR) [Member] | Sun Trust Revolving Credit Facility [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Applicable margin (percent)			1.75%
Minimum [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Applicable margin (percent)									2.25%
Maximum [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Applicable margin (percent)									3.50%
Subsequent Event [Member] | Sun Trust Revolving Credit Facility [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity of credit facility												$ 35,000,000.0	$ 20,000,000.0
Scenario, Forecast [Member] | Sun Trust Revolving Credit Facility [Member] | SunTrust Bank [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity of credit facility										$ 30,000,000.0