General Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
New Accounting Pronouncements And Change In Accounting Principals [Line Items]
Deferred policy acquisition costs	$ 202,322		$ 202,322		$ 191,960
Accounts payable and accrued liabilities	527,260		527,260		875,574
Retained earnings	2,917,086		2,917,086		2,756,166
Policy acquisition costs, net	70,796	74,490	137,745	143,934
Other operating expense	$ 87,719	$ 80,424	$ 164,572	$ 167,706