CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)	Noncontrolling Interest
Beginning balance (deficit) at Dec. 31, 2012	$ 187.0	$ 0.0	$ 236.4	$ (0.4)	$ (49.8)	$ 0.8
Beginning balance (in shares) at Dec. 31, 2012		21,870,770
Increase (Decrease) in Stockholders' Equity
Net income	14.8				12.1	2.7
Foreign currency translation adjustments	(0.5)			(0.5)
Effective portion of cash flow hedge	1.0			1.0
Shares issued—Central Merger	0.0
Issuance of stock grants	0.0
Issuance of stock grants (in shares)		15,576
Vested restricted stock units	$ 0.0
Vested restricted stock units (in shares)		90,965
Proceeds from exercise of stock options (in shares)	0
Non-cash stock-based compensation related to restricted stock units and performance share units	$ 4.1		4.1
Tax benefit from vesting of restricted stock	0.2		0.2
Distribution to noncontrolling interest	(2.8)					(2.8)
Ending balance (deficit) at Dec. 31, 2013	203.7	$ 0.0	240.7	0.1	(37.7)	0.6
Ending balance (in shares) at Dec. 31, 2013		21,977,311
Increase (Decrease) in Stockholders' Equity
Net income	26.1				23.1	3.0
Foreign currency translation adjustments	(0.2)			(0.2)
Effective portion of cash flow hedge	(0.2)			(0.2)
Issuance of stock grants	$ 0.5		0.5
Issuance of stock grants (in shares)		19,336
Vested restricted stock units (in shares)		131,078
Proceeds from exercise of stock options (in shares)	0
Non-cash stock-based compensation related to restricted stock units and performance share units	$ (2.8)		2.8
Tax benefit from vesting of restricted stock	(0.1)		(0.1)
Distribution to noncontrolling interest	(2.9)					(2.9)
Ending balance (deficit) at Dec. 31, 2014	$ 229.8	$ 0.0	243.9	(0.2)	(14.6)	0.7
Ending balance (in shares) at Dec. 31, 2014	22,127,725	22,127,725
Increase (Decrease) in Stockholders' Equity
Net income	$ 20.3				17.4	2.9
Foreign currency translation adjustments	(0.7)			(0.7)
Effective portion of cash flow hedge	(0.2)			(0.2)
Issuance of stock grants	0.7		0.7
Issuance of stock grants (in shares)		29,305
Vested restricted stock units	0.0
Vested restricted stock units (in shares)		164,447
Proceeds from exercise of stock options	0.0
Proceeds from exercise of stock options (in shares)		7,101
Non-cash stock-based compensation related to restricted stock units and performance share units	3.0		3.0
Tax benefit from vesting of restricted stock	0.3		0.3
Distribution to noncontrolling interest	(3.1)					(3.1)
Ending balance (deficit) at Dec. 31, 2015	$ 250.1	$ 0.0	$ 247.9	$ (1.1)	$ 2.8	$ 0.5
Ending balance (in shares) at Dec. 31, 2015	22,127,725	22,328,578