Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Paid-in Capital in Excess of par	Accumulated Other Comprehensive Income	Retained Earnings	Total
Balances at Dec. 31, 2012	$ 87	$ 47,785	$ (538)	$ 151,829	$ 199,163
Balances (in shares) at Dec. 31, 2012	8,716
Increase (Decrease) in Shareholders' Equity
Net income				15,626	15,626
Net unrealized loss from derivative instruments, net of tax benefit			863		863
Shares repurchased	$ (4)	(5,914)			(5,918)
Shares repurchased (in shares)	(395)
Shares issued under stock compensation plans	$ 2	678			680
Shares issued under stock compensation plans (in shares)	160
Cancellation of restricted stock units in satisfaction of withholding tax	$ (1)	(1,247)			(1,248)
Cancellation of restricted stock units in satisfaction of withholding tax (in shares)	(81)
Stock-based compensation, net of forfeitures		3,439			3,439
Balances at Dec. 31, 2013	$ 84	44,741	325	167,455	212,605
Balances (in shares) at Dec. 31, 2013	8,400
Increase (Decrease) in Shareholders' Equity
Net income				7,247	7,247
Net unrealized loss from derivative instruments, net of tax benefit			(325)		(325)
Shares repurchased	$ (2)	(5,350)			(5,352)
Shares repurchased (in shares)	(249)
Shares issued under stock compensation plans	$ 2	408			410
Shares issued under stock compensation plans (in shares)	272
Cancellation of restricted stock units in satisfaction of withholding tax	$ (1)	(1,543)			(1,544)
Cancellation of restricted stock units in satisfaction of withholding tax (in shares)	(77)
Stock-based compensation, net of forfeitures		3,509			3,509
Tax benefit on disqualified disposition of shares		311			311
Balances at Dec. 31, 2014	$ 83	42,076		174,702	216,861
Balances (in shares) at Dec. 31, 2014	8,346
Increase (Decrease) in Shareholders' Equity
Net income				7,356	7,356
Net unrealized loss from derivative instruments, net of tax benefit			(521)		(521)
Shares repurchased	$ (9)	(16,491)			(16,500)
Shares repurchased (in shares)	(912)
Shares issued under stock compensation plans	$ 2	516			518
Shares issued under stock compensation plans (in shares)	205
Cancellation of restricted stock units in satisfaction of withholding tax	$ (1)	(1,557)			(1,558)
Cancellation of restricted stock units in satisfaction of withholding tax (in shares)	(91)
Stock-based compensation, net of forfeitures		4,150			4,150
Tax benefit on disqualified disposition of shares		26			26
Balances at Dec. 31, 2015	$ 75	$ 28,720	$ (521)	$ 182,058	$ 210,332
Balances (in shares) at Dec. 31, 2015	7,548