Consolidated Statements of Stockholders' Equity (Parenthetical) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Exercise of stock options	348	184	240
Employee stock purchase plan sales, shares	110	94	51
Sale of common stock, shares	4,774	437	761
Purchases of treasury stock, shares		12	1
Common Stock
Exercise of stock options	348	184	240
Employee stock purchase plan sales, shares	110	94	51
Sale of common stock, shares	4,774	437	761
Additional Paid-In Capital
Exercise of stock options	348	184	240
Employee stock purchase plan sales, shares	110	94	51
Sale of common stock, shares	4,774	437	761
Purchases of treasury stock, shares		12	1