Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax asset:
Loss reserve discounting	$ 87,394	$ 119,547
Unearned premiums	149,107	132,014
Other-than-temporary impairments	49,483	62,187
Restricted stock units	52,671	49,553
Other	92,698	83,740
Gross deferred tax asset	431,353	447,041
Less valuation allowance	0	0
Deferred tax asset	431,353	447,041
Deferred tax liability:
Amortization of intangibles	11,886	12,458
Deferred policy acquisition costs	136,635	120,532
Unrealized investment gains	148,215	274,497
Other	114,497	99,809
Deferred tax liability	411,233	507,296
Net deferred tax asset (liability)	20,120	(60,255)
Current taxes payables		22,546
Current Federal income taxes	24,737	0
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 870