Acquisitions, Dispositions and Goodwill (Tables)

12 Months Ended

Dec. 31, 2012

Acquisitions Dispositions And Goodwill [Abstract]

Goodwill balances by reportable segments

	U.S. Property		Professional		Accident		U.S. Surety
	& Casualty		Liability		& Health		& Credit		International		Total
Balance at December 31, 2010	$	223,000	$	249,820	$	144,128	$	79,700	$	125,000	$	821,648
Earnout and other		0		51,727		4		0		(565)		51,166
Balance at December 31, 2011		223,000		301,547		144,132		79,700		124,435		872,814
Earnout and other		0		12,542		(19)		0		523		13,046
Balance at December 31, 2012	$	223,000	$	314,089	$	144,113	$	79,700	$	124,958	$	885,860