Consolidated Condensed Schedule Of Investments (Investments Sold Short) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2017		Dec. 31, 2016
Investments Sold, Not yet Purchased [Line Items]
Investments sold short, at fair value-		$ (780,320)		$ (584,896)
Proceeds from investments sold short		$ 782,395		$ 589,429
TBA - Fixed Rate Agency Securities Sold Short [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(80.01%)	[1],[2],[3]	(62.77%)	[4],[5],[6]
Current Principal/Notional Amount		$ (502,617)		$ (384,155)
Investments sold short, at fair value-		(523,620)	[1],[3]	(404,728)	[4],[6]
Proceeds from investments sold short		$ (521,631)	[1],[3]	$ (404,967)	[4],[6]
TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(58.47%)		(32.67%)
TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal Home Loan Mortgage Corporation [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(18.96%)		(22.21%)
TBA - Fixed Rate Agency Securities Sold Short [Member] | Government National Mortgage Association [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(2.58%)		(7.89%)
Government debt [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(25.22%)	[2],[3]	(20.54%)	[5],[6]
Investments sold short, at fair value-		$ (165,080)	[3]	$ (132,442)	[6]
Proceeds from investments sold short		$ (168,943)	[3]	$ (136,746)	[6]
Common Stock Sold Short [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(0.33%)	[2],[3]	(1.26%)	[5],[6]
Investments sold short, at fair value-		$ (2,154)	[3]	$ (8,154)	[6]
Proceeds from investments sold short		$ (2,223)	[3]	$ (8,052)	[6]
Corporate Debt Sold Short [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(13.67%)	[2],[3]	(6.14%)	[5],[6]
Investments sold short, at fair value-		$ (89,466)	[3]	$ (39,572)	[6]
Proceeds from investments sold short		$ (89,598)	[3]	$ (39,664)	[6]
Investments Sold Short [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(119.23%)	[2],[3]	(90.71%)	[5],[6]
Investments sold short, at fair value-		$ (780,320)	[3]	$ (584,896)	[6]
Proceeds from investments sold short		$ (782,395)	[3]	$ (589,429)	[6]
North America [Member] | US Government Debt Securities [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(15.56%)	[2],[3]	(10.82%)	[5],[6]
Investments sold short, at fair value-		$ (101,820)	[3]	$ (69,762)	[6]
Proceeds from investments sold short		$ (102,205)	[3]	$ (69,946)	[6]
Europe [Member] | Foreign Government Debt Securities [Member]
Investments Sold, Not yet Purchased [Line Items]
Investment Sold, Not yet Purchased, Percent of Equity		(9.66%)	[2],[3]	(9.72%)	[5],[6]
Investments sold short, at fair value-		$ (63,260)	[3]	$ (62,680)	[6]
Proceeds from investments sold short		(66,738)	[3]	(66,800)	[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 year) 3.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (111,872)	[1],[3]	$ (24,352)	[4],[6]
Rate		3.50%	[1],[3]	3.50%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (114,420)	[1],[3]	$ (24,960)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal Home Loan Mortgage Corporation (30 Year) 4 Point 00 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (87,067)	[1],[3]	$ (87,767)	[4],[6]
Rate		4.00%	[1],[3]	4.00%	[4],[6]
Investments maturity date		2017-05	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (91,135)	[1],[3]	$ (92,210)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 3.50% 2017 05 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[1],[3]	$ (85,000)
Rate	[1],[3]	3.50%
Investments maturity date	[1],[3]	2017-05
Investments sold short, at fair value-	[1],[3]	$ (86,760)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 4 Point 50 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (63,640)	[1],[3]	$ (50,930)	[4],[6]
Rate		4.50%	[1],[3]	4.50%	[4],[6]
Investments maturity date		2017-05	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (68,137)	[1],[3]	$ (54,748)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 4.00% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (38,000)	[1],[3]	$ (26,000)	[4],[6]
Rate		4.00%	[1],[3]	4.00%	[4],[6]
Investments maturity date		2017-05	[1],[3]	2017-02	[4],[6]
Investments sold short, at fair value-		$ (39,778)	[1],[3]	$ (27,295)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 5 Point 00 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (29,390)	[1],[3]	$ (31,620)	[4],[6]
Rate		5.00%	[1],[3]	5.00%	[4],[6]
Investments maturity date		2017-05	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (32,073)	[1],[3]	$ (34,426)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal Home Loan Mortgage Corporation (30 Year) 4.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (25,151)	[1],[3]	$ (23,151)	[4],[6]
Rate		4.50%	[1],[3]	4.50%	[4],[6]
Investments maturity date		2017-05	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (26,907)	[1],[3]	$ (24,840)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Government National Mortgage Association (30 Year) 3.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (14,430)	[1],[3]	$ (21,940)	[4],[6]
Rate		3.50%	[1],[3]	3.50%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (14,952)	[1],[3]	$ (22,819)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 3.00% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (11,112)	[1],[3]	$ (4,612)	[4],[6]
Rate		3.00%	[1],[3]	3.00%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (11,016)	[1],[3]	$ (4,584)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (15 Year) 2.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[1],[3]	$ (8,910)
Rate	[1],[3]	2.50%
Investments maturity date	[1],[3]	2017-05
Investments sold short, at fair value-	[1],[3]	$ (8,903)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (15 Year) 3.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[1],[3]	$ (8,260)
Rate	[1],[3]	3.50%
Investments maturity date	[1],[3]	2017-05
Investments sold short, at fair value-	[1],[3]	$ (8,589)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 5.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (6,860)	[1],[3]	$ (6,860)	[4],[6]
Rate		5.50%	[1],[3]	5.50%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (7,625)	[1],[3]	$ (7,622)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (15 Year) 4.00% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (4,900)	[1],[3]	$ (11,170)	[4],[6]
Rate		4.00%	[1],[3]	4.00%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (5,063)	[1],[3]	$ (11,494)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal Home Loan Mortgage Corporation (30 Year) 3.00% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (3,155)	[1],[3]	$ (3,155)	[4],[6]
Rate		3.00%	[1],[3]	3.00%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (3,126)	[1],[3]	$ (3,134)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal Home Loan Mortgage Corporation (15 Year) 3 Point 50 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (2,780)	[1],[3]	$ (8,790)	[4],[6]
Rate		3.50%	[1],[3]	3.50%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (2,896)	[1],[3]	$ (9,169)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Government National Mortgage Association (30 Year) 4.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (1,800)	[1],[3]	$ (15,770)	[4],[6]
Rate		4.50%	[1],[3]	4.50%	[4],[6]
Investments maturity date		2017-04	[1],[3]	2017-01	[4],[6]
Investments sold short, at fair value-		$ (1,923)	[1],[3]	$ (17,058)	[4],[6]
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal Home Loan Mortgage Corporation (15 Year) 3 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[4],[6]			$ (13,510)
Rate	[4],[6]			3.00%
Investments maturity date	[4],[6]			2017-01
Investments sold short, at fair value-	[4],[6]			$ (13,869)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 5 Point 00 Percent 201704 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[1],[3]	$ (290)
Rate	[1],[3]	5.00%
Investments maturity date	[1],[3]	2017-04
Investments sold short, at fair value-	[1],[3]	$ (317)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (30 Year) 4.00% 2017 01 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[4],[6]			$ (20,558)
Rate	[4],[6]			4.00%
Investments maturity date	[4],[6]			2017-01
Investments sold short, at fair value-	[4],[6]			$ (21,611)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (15 Year) 3.00% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[4],[6]			$ (20,740)
Rate	[4],[6]			3.00%
Investments maturity date	[4],[6]			2017-01
Investments sold short, at fair value-	[4],[6]			$ (21,285)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Government National Mortgage Association (30 Year) 3.00% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[4],[6]			$ (6,500)
Rate	[4],[6]			3.00%
Investments maturity date	[4],[6]			2017-01
Investments sold short, at fair value-	[4],[6]			$ (6,568)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Federal National Mortgage Association (15 Year) 3.50% [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[4],[6]			$ (2,530)
Rate	[4],[6]			3.50%
Investments maturity date	[4],[6]			2017-02
Investments sold short, at fair value-	[4],[6]			$ (2,633)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Government National Mortgage Association (30 Year) 3.50% 2017 02 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[4],[6]			$ (2,500)
Rate	[4],[6]			3.50%
Investments maturity date	[4],[6]			2017-02
Investments sold short, at fair value-	[4],[6]			$ (2,597)
Mortgage-related Residential [Member] | North America [Member] | TBA - Fixed Rate Agency Securities Sold Short [Member] | Government National Mortgage Association (30 Year) 4 Point 00 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[4],[6]			$ (1,700)
Rate	[4],[6]			4.00%
Investments maturity date	[4],[6]			2017-01
Investments sold short, at fair value-	[4],[6]			$ (1,806)
Government [Member] | North America [Member] | US Government Debt Securities [Member] | U.S. Treasury Note, 2.00 Percent, Maturity Date 2026 11 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (35,153)	[3]	$ (48,133)	[6]
Rate		2.00%	[3]	2.00%	[6]
Investments maturity date		2026-11	[3]	2026-11	[6]
Investments sold short, at fair value-		$ (33,964)	[3]	$ (46,287)	[6]
Government [Member] | North America [Member] | US Government Debt Securities [Member] | U.S. Treasury Note, 2.25 Percent, Maturity Date 2027 02 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[3]	$ (26,640)
Rate	[3]	2.25%
Investments maturity date	[3]	2027-02
Investments sold short, at fair value-	[3]	$ (26,305)
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.88 Percent, Maturity Date 2022 02 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[3]	$ (21,139)
Rate	[3]	1.88%
Investments maturity date	[3]	2022-02
Investments sold short, at fair value-	[3]	$ (21,096)
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.50 Percent, Maturity Date 2026 08 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (12,160)	[3]	$ (12,160)	[6]
Rate		1.50%	[3]	1.50%	[6]
Investments maturity date		2026-08	[3]	2026-08	[6]
Investments sold short, at fair value-		$ (11,253)	[3]	$ (11,179)	[6]
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.75 Percent, Maturity Date 2021 11 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (3,696)	[3]	$ (4,726)	[6]
Rate		1.75%	[3]	1.75%	[6]
Investments maturity date		2021-11	[3]	2021-11	[6]
Investments sold short, at fair value-		$ (3,672)	[3]	$ (4,690)	[6]
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.13 Percent, Maturity Date 2021 08 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (2,880)	[3]	$ (3,230)	[6]
Rate		1.13%	[3]	1.13%	[6]
Investments maturity date		2021-08	[3]	2021-08	[6]
Investments sold short, at fair value-		$ (2,791)	[3]	$ (3,121)	[6]
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.25 Percent, Maturity Date 2021 10 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (1,343)	[3]	$ (800)	[6]
Rate		1.25%	[3]	1.25%	[6]
Investments maturity date		2021-10	[3]	2021-10	[6]
Investments sold short, at fair value-		$ (1,306)	[3]	$ (776)	[6]
Government [Member] | North America [Member] | US Government Debt Securities [Member] | U.S. Treasury Bond, 2.25 Percent, Maturity Date 2046 08 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[3]	$ (930)
Rate	[3]	2.25%
Investments maturity date	[3]	2046-08
Investments sold short, at fair value-	[3]	$ (787)
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.13 Percent, Maturity Date 2021 09 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (668)	[3]	$ (1,968)	[6]
Rate		1.13%	[3]	1.13%	[6]
Investments maturity date		2021-09	[3]	2021-09	[6]
Investments sold short, at fair value-		$ (646)	[3]	$ (1,898)	[6]
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.38 Percent, Maturity Date 2021 04 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[6]			$ (1,305)
Rate	[6]			1.38%
Investments maturity date	[6]			2021-04
Investments sold short, at fair value-	[6]			$ (1,280)
Government [Member] | North America [Member] | US Government Debt Securities [Member] | US Treasury Note, 1.13 Percent, Maturity Date 2021 07 [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[6]			$ (549)
Rate	[6]			1.13%
Investments maturity date	[6]			2021-07
Investments sold short, at fair value-	[6]			$ (531)
Government [Member] | Europe [Member] | Foreign Government Debt Securities [Member] | Sovereign Debt Securities [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (21,046)	[3]	$ (20,754)	[6]
Investments maturity date		2020-11	[3]	2020-11	[6]
Investments sold short, at fair value-		$ (21,306)	[3]	$ (21,219)	[6]
Government [Member] | Europe [Member] | Foreign Government Debt Securities [Member] | Spanish Sovereign Bond, 0.25 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (14,711)	[3]	$ (14,507)	[6]
Rate		0.25%	[3]	0.25%	[6]
Investments maturity date		2018-04	[3]	2018-04	[6]
Investments sold short, at fair value-		$ (14,798)	[3]	$ (14,614)	[6]
Government [Member] | Europe [Member] | Foreign Government Debt Securities [Member] | Spanish Sovereign Bond, 0.75 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (9,305)	[3]	$ (9,176)	[6]
Rate		0.75%	[3]	0.75%	[6]
Investments maturity date		2021-07	[3]	2021-07	[6]
Investments sold short, at fair value-		$ (9,513)	[3]	$ (9,379)	[6]
Government [Member] | Europe [Member] | Foreign Government Debt Securities [Member] | Spanish Sovereign Bond, 2.75 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (8,439)	[3]	$ (8,322)	[6]
Rate		2.75%	[3]	2.75%	[6]
Investments maturity date		2019-04	[3]	2019-04	[6]
Investments sold short, at fair value-		$ (8,953)	[3]	$ (8,888)	[6]
Government [Member] | Europe [Member] | Foreign Government Debt Securities [Member] | Spanish Sovereign Bond, 1.15 Percent [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (8,372)	[3]	$ (8,257)	[6]
Rate		1.15%	[3]	1.15%	[6]
Investments maturity date		2020-07	[3]	2020-07	[6]
Investments sold short, at fair value-		$ (8,690)	[3]	$ (8,580)	[6]
Government [Member] | Europe [Member] | Foreign Government Debt Securities [Member] | Minimum [Member] | Sovereign Debt Securities [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		0.25%	[3]	0.25%	[6]
Government [Member] | Europe [Member] | Foreign Government Debt Securities [Member] | Maximum [Member] | Sovereign Debt Securities [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		0.65%	[3]	0.65%	[6]
Basic Materials [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (5,870)	[3]	$ (8,970)	[6]
Investments sold short, at fair value-		$ (5,588)	[3]	$ (8,717)	[6]
Basic Materials [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Minimum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		3.88%	[3]	3.88%	[6]
Investments maturity date		2021-11	[3]	2021-10	[6]
Basic Materials [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Maximum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		4.00%	[3]	5.13%	[6]
Investments maturity date		2023-03	[3]	2023-03	[6]
Communications [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (16,830)	[3]	$ (8,750)	[6]
Investments sold short, at fair value-		$ (16,403)	[3]	$ (8,551)	[6]
Communications [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Minimum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		6.00%	[3]	5.25%	[6]
Investments maturity date		2021-07	[3]	2021-07	[6]
Communications [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Maximum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		9.25%	[3]	9.25%	[6]
Investments maturity date		2023-10	[3]	2022-09	[6]
Consumer [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (38,620)	[3]	$ (8,930)	[6]
Investments sold short, at fair value-		$ (38,413)	[3]	$ (8,695)	[6]
Consumer [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Minimum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		2.55%	[3]	3.88%	[6]
Investments maturity date		2019-04	[3]	2022-01	[6]
Consumer [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Maximum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		8.13%	[3]	6.88%	[6]
Investments maturity date		2024-10	[3]	2026-04	[6]
Energy [Member] | North America [Member] | Common Stock Sold Short [Member] | Exchange Traded Equity [Member]
Investments Sold, Not yet Purchased [Line Items]
Investments sold short, at fair value-	[3]	$ (2,154)
Investment Sold, Not yet Purchased, Balance, Shares	[3]	(61)
Energy [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (25,207)	[3]	$ (10,597)	[6]
Investments sold short, at fair value-		$ (24,039)	[3]	$ (10,041)	[6]
Energy [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Minimum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		2.40%	[3]	2.40%	[6]
Investments maturity date		2022-04	[3]	2021-06	[6]
Energy [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Maximum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate		8.00%	[3]	8.00%	[6]
Investments maturity date		2025-01	[3]	2025-01	[6]
Financial [Member] | North America [Member] | Common Stock Sold Short [Member] | Exchange Traded Equity [Member]
Investments Sold, Not yet Purchased [Line Items]
Investments sold short, at fair value-	[6]			$ (8,154)
Investment Sold, Not yet Purchased, Balance, Shares	[6]			(207)
Financial [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (1,610)	[3]	$ (1,130)	[6]
Rate	[6]			4.13%
Investments maturity date	[6]			2022-02
Investments sold short, at fair value-		$ (1,615)	[3]	$ (1,121)	[6]
Financial [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Minimum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate	[3]	4.13%
Investments maturity date	[3]	2022-02
Financial [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Maximum [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Rate	[3]	5.38%
Investments maturity date	[3]	2023-12
Industrial Sector [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[3]	$ (880)
Rate	[3]	7.25%
Investments maturity date	[3]	2022-10
Investments sold short, at fair value-	[3]	$ (953)
Technology Sector [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount	[3]	$ (1,490)
Rate	[3]	6.38%
Investments maturity date	[3]	2023-12
Investments sold short, at fair value-	[3]	$ (1,576)
Utilities [Member] | North America [Member] | Corporate Debt Sold Short [Member] | Various Issuer [Member]
Investments Sold, Not yet Purchased [Line Items]
Current Principal/Notional Amount		$ (860)	[3]	$ (2,430)	[6]
Rate		6.25%	[3]	6.25%	[6]
Investments maturity date		2022-07	[3]	2022-07	[6]
Investments sold short, at fair value-		$ (879)	[3]	$ (2,447)	[6]

[1] At March 31, 2017, the Company's short investments guaranteed by the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation, and the Government National Mortgage Association, represented 58.47%, 18.96%, and 2.58% of equity, respectively.

[2] Classification percentages are based on Total Equity.

[3] See Note 2 and Note 3 in Notes to Consolidated Financial Statements.

[4] At December 31, 2016, the Company's short investments guaranteed by the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation, and the Government National Mortgage Association, represented 32.67%, 22.21%, and 7.89% of equity, respectively.

[5] Classification percentages are based on Total Equity.

[6] See Note 2 and Note 3 in Notes to Consolidated Financial Statements.