Quarterly Results of Operations (Unaudited) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
QuarterlyFinancialDataAbstract
Total revenues	$ 309,786	$ 283,524	$ 621,035	$ 574,100
Total benefits and expenses	242,370	96,720	459,266	189,910
Income Loss From Continuing Operations Before Income Taxes And Operating Joint Ventures	67,416	186,804	161,769	384,190
Net income	$ 57,431	$ 143,670	$ 134,929	$ 291,058