INVESTMENTS (Details 4) (USD $)	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Fixed income securities in unrealized loss positions
Book Value	$ 331,887,000	$ 116,840,000
Fair Value	324,394,000	110,187,000
Unrealized Loss	(7,493,000)	(6,653,000)
Cash	70,306,000	81,184,000	0	0
Short-term investments, at cost	58,451,000	23,865,000
Subtotal, debt securities
Fixed income securities in unrealized loss positions
Book Value	316,013,000	88,344,000
Fair Value	310,002,000	84,235,000
Unrealized Loss	(6,011,000)	(4,109,000)
Percent to Total	100.00%
Number of unrealized loss positions	92
Percentage of unrealized loss to fixed income portfolio	0.40%
Number of securities in unrealized loss positions for 12 months or longer	6
Maximum unrealized loss on securities in unrealized loss position for twelve consecutive month or longer	800,000
Common Stock
Fixed income securities in unrealized loss positions
Book Value	15,874,000	28,496,000
Fair Value	14,392,000	25,952,000
Unrealized Loss	(1,482,000)	(2,544,000)
Number of unrealized loss positions	20
Cash and Short-term Investments
Fixed income securities in unrealized loss positions
Short-term investments, at cost	58,500,000	23,900,000
NAIC Rating 1 | Subtotal, debt securities
Fixed income securities in unrealized loss positions
Book Value	300,444,000
Fair Value	294,680,000
Unrealized Loss	(5,764,000)
Percent to Total	95.90%
NAIC Rating 2 | Subtotal, debt securities
Fixed income securities in unrealized loss positions
Book Value	15,569,000
Fair Value	15,322,000
Unrealized Loss	$ (247,000)
Percent to Total	4.10%