INVESTMENTS (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
INVESTMENTS
Unrealized losses relative to total invested assets (as a percent)	0.30%
Fair value
Less than 12 months	$ 112,876	$ 682,254
12 Months and Greater	245,333	3,188
Total Fair value	358,209	685,442
Cost or amortized Cost
Less than 12 months	113,352	710,949
12 months and greater	250,530	3,426
Total Cost or Amortized Cost	363,882	714,375
Unrealized Loss
Less than 12 months	(476)	(28,695)
12 Months and Greater	(5,197)	(238)
Total Unrealized Loss	(5,673)	(28,933)
Cash and Short-term Investments
Cash	27,234	39,469	12,757	44,314
Short-term investments, at cost which approximates fair value	18,489	23,232
Debt securities
Fair value
Less than 12 months	103,504	679,860
12 Months and Greater	245,333	3,188
Total Fair value	348,837	683,048
Cost or amortized Cost
Less than 12 months	103,914	708,280
12 months and greater	250,530	3,426
Total Cost or Amortized Cost	354,444	711,706
Unrealized Loss
Less than 12 months	(410)	(28,420)
12 Months and Greater	(5,197)	(238)
Total Unrealized Loss	(5,607)	(28,658)
Percent to Total	100.00%
Debt securities | NAIC Rating 1 | AAA/AA/A | Aaa/Aa/A
Fair value
Total Fair value	315,595
Cost or amortized Cost
Total Cost or Amortized Cost	321,030
Unrealized Loss
Total Unrealized Loss	(5,435)
Percent to Total	96.90%
Debt securities | NAIC Rating 2 | BBB | Baa
Fair value
Total Fair value	9,226
Cost or amortized Cost
Total Cost or Amortized Cost	9,251
Unrealized Loss
Total Unrealized Loss	(25)
Percent to Total	0.40%
Debt securities | NAIC Rating 3 | BB | Ba
Fair value
Total Fair value	15,048
Cost or amortized Cost
Total Cost or Amortized Cost	15,137
Unrealized Loss
Total Unrealized Loss	(89)
Percent to Total	1.60%
Debt securities | NAIC Rating 4 | B | B
Fair value
Total Fair value	8,316
Cost or amortized Cost
Total Cost or Amortized Cost	8,371
Unrealized Loss
Total Unrealized Loss	(55)
Percent to Total	1.00%
Debt securities | NAIC Rating 5 | CCC or lower | Caa or lower
Fair value
Total Fair value	652
Cost or amortized Cost
Total Cost or Amortized Cost	655
Unrealized Loss
Total Unrealized Loss	(3)
Percent to Total	0.10%
U.S. Government
Fair value
Less than 12 months	4,423
Total Fair value	4,423
Cost or amortized Cost
Less than 12 months	4,433
Total Cost or Amortized Cost	4,433
Unrealized Loss
Less than 12 months	(10)
Total Unrealized Loss	(10)
U.S. Agency
Fair value
Less than 12 months	1,883	5,760
Total Fair value	1,883	5,760
Cost or amortized Cost
Less than 12 months	1,884	5,997
Total Cost or Amortized Cost	1,884	5,997
Unrealized Loss
Less than 12 months	(1)	(237)
Total Unrealized Loss	(1)	(237)
Non-U.S. Government
Fair value
Less than 12 months		1,825
Total Fair value		1,825
Cost or amortized Cost
Less than 12 months		1,890
Total Cost or Amortized Cost		1,890
Unrealized Loss
Less than 12 months		(65)
Total Unrealized Loss		(65)
Mortgage-backed
Fair value
Less than 12 months	7,349	118,283
12 Months and Greater	79,004
Total Fair value	86,353	118,283
Cost or amortized Cost
Less than 12 months	7,392	124,034
12 months and greater	81,396
Total Cost or Amortized Cost	88,788	124,034
Unrealized Loss
Less than 12 months	(43)	(5,751)
12 Months and Greater	(2,392)
Total Unrealized Loss	(2,435)	(5,751)
ABS/CMBS
Fair value
Less than 12 months	16,557	54,115
12 Months and Greater	16,457
Total Fair value	33,014	54,115
Cost or amortized Cost
Less than 12 months	16,659	56,014
12 months and greater	16,838
Total Cost or Amortized Cost	33,497	56,014
Unrealized Loss
Less than 12 months	(102)	(1,899)
12 Months and Greater	(381)
Total Unrealized Loss	(483)	(1,899)
Corporate
Fair value
Less than 12 months	51,213	190,470
12 Months and Greater	32,233	2,245
Total Fair value	83,446	192,715
Cost or amortized Cost
Less than 12 months	51,414	198,250
12 months and greater	32,829	2,477
Total Cost or Amortized Cost	84,243	200,727
Unrealized Loss
Less than 12 months	(201)	(7,780)
12 Months and Greater	(596)	(232)
Total Unrealized Loss	(797)	(8,012)
Municipal
Fair value
Less than 12 months	22,079	309,407
12 Months and Greater	117,639	943
Total Fair value	139,718	310,350
Cost or amortized Cost
Less than 12 months	22,132	322,095
12 months and greater	119,467	949
Total Cost or Amortized Cost	141,599	323,044
Unrealized Loss
Less than 12 months	(53)	(12,688)
12 Months and Greater	(1,828)	(6)
Total Unrealized Loss	(1,881)	(12,694)
Equity securities
Fair value
Less than 12 months	9,372	2,394
Total Fair value	9,372	2,394
Cost or amortized Cost
Less than 12 months	9,438	2,669
Total Cost or Amortized Cost	9,438	2,669
Unrealized Loss
Less than 12 months	(66)	(275)
Total Unrealized Loss	$ (66)	$ (275)