CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Treasury Stock
Balance at Dec. 31, 2012	$ 462,874	$ 923	$ 271,962	$ 210,003	$ (20,014)
Balance (in shares) at Dec. 31, 2012		92,374,539			5,424,847
Increase (Decrease) in Shareholders' Equity
Net income and comprehensive income	28,904			28,904
Stock-based compensation cost	8,749		8,749
Exercise of stock options	7,381	8	7,373
Exercise of stock options (in shares)		881,993
Vesting of restricted stock awards and units, net of shares withheld for employee tax	(1,498)	1	(1,499)
Vesting of restricted stock awards and units, net of shares withheld for employee tax (in shares)		102,358
Excess tax benefit from exercise of stock options	5,154		5,154
Balance at Sep. 30, 2013	$ 511,564	$ 932	$ 291,739	$ 238,907	$ (20,014)
Balance (in shares) at Sep. 30, 2013		93,358,890			5,424,847