Summary of Significant Accounting Policies - Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effect on income before income taxes	$ (305)		$ (366)	$ (624)	$ (708)
Effect on income taxes	35		51	70	98
Effect on net income	$ (270)		$ (315)	$ (554)	$ (610)
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of period (in shares)		1,841,567		1,841,567	1,627,477
Granted (in shares)				145,000	350,075
Exercised (in shares)				(21,155)	(9,188)
Forfeited (in shares)				(67,453)	(62,116)
Outstanding at end of period (in shares)	1,897,959		1,906,248	1,897,959	1,906,248
Exercisable at end of period (in shares)	1,357,459		1,170,018	1,357,459	1,170,018
Weighted average fair value of options granted during the period (usd per share)				$ 3.04	$ 3.04
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at beginning of period, Weighted Average Exercise Price (usd per share)		$ 8.15		8.15	9.11
Granted, Weighted Average Exercise Price (usd per share)				5.23	5.25
Exercised, Weighted Average Exercise Price (usd per share)				4.46	3.27
Forfeited, Weighted Average Exercise Price (usd per share)				12.27	13.87
Outstanding at end of period, Weighted Average Exercise Price (usd per share)	$ 7.83		$ 8.29	7.83	8.29
Exercisable at end of period, Weighted Average Exercise Price (usd per share)	$ 8.32		$ 9.16	$ 8.32	$ 9.16
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Risk free interest rate				2.00%	2.00%
Expected life				6 years	6 years
Dividend rate				0.00%	0.00%
Volatility				63.00%	63.00%
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option expiration period		10 years
Option vesting period				4 years
Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period				6 months
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning Outstanding (in shares)		0		0	13,540
Released (in shares)				0	(13,540)
Ending Outstanding (in shares)	0		0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning Outstanding, Weighted Average Grant Date Fair Value (usd per share)		$ 0.00		$ 0.00	$ 7.98
Released, Weighted Average Grant Date Fair Value (usd per share)				0.00	7.98
Ending Outstanding, Weighted Average Grant Date Fair Value (usd per share)	$ 0.00		$ 0.00	$ 0.00	$ 0.00
Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period				4 years
Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period				2 years