Mortgage Loans on Real Estate (Schedule of Impaired Financing Receivables) (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	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Mortgage loans with an allowance, recorded investment	$ 25,681		$ 25,681		$ 30,171
Mortgage loans with no related allowance, recorded investment	2,656		2,656		3,264
Impaired mortgage loans, recorded investment	28,337		28,337		33,435
Mortgage loans with an allowance, unpaid principal balance	42,963		42,963		47,018
Mortgage loans with no related allowance, unpaid principal balance	2,656		2,656		3,264
Impaired mortgage loans, unpaid principal balance	45,619		45,619		50,282
Mortgage loans with an allowance, related allowance	(17,282)		(17,282)		(16,847)
Mortgage loans with an allowance, average recorded investment	27,054	26,232	27,236	26,885
Mortgage loans with no related allowance, average recorded investment	2,656	18,699	2,656	18,739
Impaired mortgage loans, average recorded investment	29,710	44,931	29,892	45,624
Mortgage loans with an allowance, interest income recognized	600	426	1,235	862
Mortgage loans with no related allowance, interest income recognized	13	266	0	528
Impaired mortgage loans, interest income reoognized	$ 613	$ 692	$ 1,235	$ 1,390