Deferred Policy Acquisition Costs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Deferred Policy Acquisition Costs [Abstract]
Balance, beginning of year	$ 170,579	$ 175,866	$ 200,005
Acquisition costs deferred	482,572	500,278	519,168
Amortization	(481,721)	(505,565)	(543,307)
Balance, end of year	$ 171,430	$ 170,579	$ 175,866