CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Issuance of shares of common stock pursuant to various stock compensation plans and agreements, shares	193,831	205,103
Cancellation of common stock due to forfeitures of issued restricted stock, shares	22,050	47,489
Restricted stock surrendered due to employee tax liability, shares	344,423	60,073
Purchase of treasury stock pursuant to the Stock Repurchase Program, shares	3,543,100	4,554,827