INVESTMENTS Unrealized Losses (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Investment positions with unrealized losses
Unrealized losses relative to total invested assets (as a percent)		0.30%
Fair value
Less than 12 months		$ 138,365	$ 500,405
12 Months and Greater		41,858	44,476
Total Fair value		180,223	544,881
Cost or amortized Cost
Less than 12 months		139,703	514,250
12 months and greater		46,860	49,883
Total Cost or Amortized Cost		186,563	564,133
Unrealized Loss
Less than 12 months		(1,338)	(13,845)
12 Months and Greater		(5,002)	(5,407)
Total Unrealized Loss		(6,340)	(19,252)
Debt securities
Fair value
Less than 12 months		134,294	483,929
12 Months and Greater		39,633	44,476
Total Fair value		173,927	528,405
Cost or amortized Cost
Less than 12 months		135,126	496,318
12 months and greater		44,212	49,883
Total Cost or Amortized Cost		179,338	546,201
Unrealized Loss
Less than 12 months		(832)	(12,389)
12 Months and Greater		(4,579)	(5,407)
Total Unrealized Loss		$ (5,411)	(17,796)
Percent to Total		100.00%
Debt securities | NAIC Rating 1 | AAA/AA/A | Aaa/Aa/A
Fair value
Total Fair value		$ 142,648
Cost or amortized Cost
Total Cost or Amortized Cost		143,545
Unrealized Loss
Total Unrealized Loss		$ (897)
Percent to Total		16.60%
Debt securities | NAIC Rating 2 | BBB | Baa
Fair value
Total Fair value		$ 11,499
Cost or amortized Cost
Total Cost or Amortized Cost		11,779
Unrealized Loss
Total Unrealized Loss		$ (280)
Percent to Total		5.20%
Debt securities | NAIC Rating 3 | BB | Ba
Fair value
Total Fair value		$ 1,719
Cost or amortized Cost
Total Cost or Amortized Cost		1,796
Unrealized Loss
Total Unrealized Loss		$ (77)
Percent to Total		1.40%
Debt securities | NAIC Rating 4 | B
Fair value
Total Fair value		$ 14,594
Cost or amortized Cost
Total Cost or Amortized Cost		17,186
Unrealized Loss
Total Unrealized Loss		$ (2,592)
Percent to Total		47.90%
Debt securities | NAIC Rating 5 | CCC or lower
Fair value
Total Fair value		$ 3,467
Cost or amortized Cost
Total Cost or Amortized Cost		5,032
Unrealized Loss
Total Unrealized Loss		$ (1,565)
Percent to Total		28.90%
U.S. government
Fair value
Less than 12 months		$ 2,021	36,000
Total Fair value		2,021	36,000
Cost or amortized Cost
Less than 12 months		2,027	36,112
Total Cost or Amortized Cost		2,027	36,112
Unrealized Loss
Less than 12 months		(6)	(112)
Total Unrealized Loss		(6)	(112)
U.S. Agency
Fair value
Less than 12 months			8,070
Total Fair value			8,070
Cost or amortized Cost
Less than 12 months			8,117
Total Cost or Amortized Cost			8,117
Unrealized Loss
Less than 12 months			(47)
Total Unrealized Loss			(47)
Non-U.S. govt. & agency
Fair value
Less than 12 months		3,849	4,478
Total Fair value		3,849	4,478
Cost or amortized Cost
Less than 12 months		4,039	5,035
Total Cost or Amortized Cost		4,039	5,035
Unrealized Loss
Less than 12 months		(190)	(557)
Total Unrealized Loss		(190)	(557)
Agency MBS
Fair value
Less than 12 months		42,710	100,424
12 Months and Greater		9,028	18,520
Total Fair value		51,738	118,944
Cost or amortized Cost
Less than 12 months		42,789	101,473
12 months and greater		9,228	19,090
Total Cost or Amortized Cost		52,017	120,563
Unrealized Loss
Less than 12 months		(79)	(1,049)
12 Months and Greater		(200)	(570)
Total Unrealized Loss		(279)	(1,619)
ABS/CMBS
Fair value
Less than 12 months	[1]	31,680	51,091
12 Months and Greater	[1]	6,540	8,364
Total Fair value	[1]	38,220	59,455
Cost or amortized Cost
Less than 12 months	[1]	31,848	51,562
12 months and greater	[1]	6,614	8,499
Total Cost or Amortized Cost	[1]	38,462	60,061
Unrealized Loss
Less than 12 months	[1]	(168)	(471)
12 Months and Greater	[1]	(74)	(135)
Total Unrealized Loss	[1]	(242)	(606)
Corporate
Fair value
Less than 12 months		23,768	275,404
12 Months and Greater		24,065	15,174
Total Fair value		47,833	290,578
Cost or amortized Cost
Less than 12 months		23,927	285,515
12 months and greater		28,370	19,870
Total Cost or Amortized Cost		52,297	305,385
Unrealized Loss
Less than 12 months		(159)	(10,111)
12 Months and Greater		(4,305)	(4,696)
Total Unrealized Loss		(4,464)	(14,807)
Municipal
Fair value
Less than 12 months		30,266	8,462
12 Months and Greater			2,418
Total Fair value		30,266	10,880
Cost or amortized Cost
Less than 12 months		30,496	8,504
12 months and greater			2,424
Total Cost or Amortized Cost		30,496	10,928
Unrealized Loss
Less than 12 months		(230)	(42)
12 Months and Greater			(6)
Total Unrealized Loss		(230)	(48)
Equity securities
Fair value
Less than 12 months		4,071	16,476
12 Months and Greater		2,225
Total Fair value		6,296	16,476
Cost or amortized Cost
Less than 12 months		4,577	17,932
12 months and greater		2,648
Total Cost or Amortized Cost		7,225	17,932
Unrealized Loss
Less than 12 months		(506)	(1,456)
12 Months and Greater		(423)
Total Unrealized Loss		$ (929)	$ (1,456)

[1] Non-agency asset-backed and commercial mortgage-backed