Financial Statements (Parent Only) (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues:
Investment income									$ 30,198	$ 31,338	$ 32,138
Realized (losses) gains on sales of investments									9,693	10,966	2,251
Total Revenues	79,615	77,415	70,135	69,957	68,506	68,053	68,192	73,788	297,122	278,539	239,310
Expenses:
Net loss before equity in earnings of subsidiaries	(737)	7,428	1,751	5,507	(8,062)	6,897	3,533	8,362	13,949	10,730	27,869
Net earnings									13,108	14,124	29,951
Parent Company [Member]
Revenues:
Investment income									230	126	221
Realized (losses) gains on sales of investments									65	(16)
Total Revenues									295	110	221
Expenses:
Operating expenses									3,837	2,258	2,594
Total Expenses									3,837	2,258	2,594
Net loss before equity in earnings of subsidiaries									(3,542)	(2,148)	(2,373)
Equity in net earnings of subsidiaries									15,381	12,990	32,881
Net earnings									$ 11,839	$ 10,842	$ 30,508