CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock	Capital in Excess of Par Value	Retained Earnings	Treasury Stock	Total
Balance at Dec. 31, 2014	$ 943	$ 313,214	$ 263,947	$ (45,014)	$ 533,090
Balance (in shares) at Dec. 31, 2014	94,511,444			6,526,305
Increase (Decrease) in Stockholders' Equity
Net income and comprehensive income			3,522		3,522
Stock-based compensation expense		3,245			3,245
Exercise of stock options	4	3,269			3,273
Exercise of stock options (in shares)	442,585
Vesting of restricted stock awards and units, net of shares withheld for employee tax	1	(597)			(596)
Vesting of restricted stock awards and units, net of shares withheld for employee tax (in shares)	77,661
Excess tax benefit from exercise of stock options		1,448			1,448
Shortfall due to exercise of stock options and vesting of restricted stock units		(310)			(310)
Deferred tax asset reversal for unexercised stock options		(80)			(80)
Balance at Mar. 31, 2015	$ 948	$ 320,189	$ 267,469	$ (45,014)	$ 543,592
Balance (in shares) at Mar. 31, 2015	95,031,690			6,526,305