XML 47 R35.htm IDEA: XBRL DOCUMENT v3.7.0.1
Investments (Gross Unrealized Losses on Investments, By Category and Length of Time) (Details) - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value $ 10,735,390 $ 13,195,027
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (360,136) (454,013)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 1,173,243 1,368,974
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (100,317) (130,705)
Available for sale securities, continuous unrealized loss position, total, fair value 11,908,633 14,564,001
Available for sale securities, continuous unrealized loss position, total, unrealized losses (460,453) (584,718)
United States Government Full Faith and Credit [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 7,275 7,405
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (252) (288)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 0 0
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses 0 0
Available for sale securities, continuous unrealized loss position, total, fair value 7,275 7,405
Available for sale securities, continuous unrealized loss position, total, unrealized losses (252) (288)
United States Government Sponsored Agencies [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 989,089 995,548
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (53,376) (46,913)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 0 0
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses 0 0
Available for sale securities, continuous unrealized loss position, total, fair value 989,089 995,548
Available for sale securities, continuous unrealized loss position, total, unrealized losses (53,376) (46,913)
United States Municipalities, States and Territories [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 367,378 463,409
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (18,903) (22,393)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 0 0
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses 0 0
Available for sale securities, continuous unrealized loss position, total, fair value 367,378 463,409
Available for sale securities, continuous unrealized loss position, total, unrealized losses (18,903) (22,393)
Foreign Government Obligations [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 24,941 29,158
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (147) (913)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 11,844 20,388
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (2,500) (4,167)
Available for sale securities, continuous unrealized loss position, total, fair value 36,785 49,546
Available for sale securities, continuous unrealized loss position, total, unrealized losses (2,647) (5,080)
Corporate Securities [Member] | Finance, Insurance and Real Estate Sectors [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 1,443,090 1,940,107
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (52,452) (70,421)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 109,375 82,907
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (8,578) (7,723)
Available for sale securities, continuous unrealized loss position, total, fair value 1,552,465 2,023,014
Available for sale securities, continuous unrealized loss position, total, unrealized losses (61,030) (78,144)
Corporate Securities [Member] | Manufacturing, Construction and Mining [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 721,674 1,199,420
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (20,261) (34,304)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 210,686 311,591
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (15,139) (23,273)
Available for sale securities, continuous unrealized loss position, total, fair value 932,360 1,511,011
Available for sale securities, continuous unrealized loss position, total, unrealized losses (35,400) (57,577)
Corporate Securities [Member] | Utilities and Related Sectors [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 1,342,397 1,401,650
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (33,268) (45,015)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 53,702 58,597
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (4,018) (5,820)
Available for sale securities, continuous unrealized loss position, total, fair value 1,396,099 1,460,247
Available for sale securities, continuous unrealized loss position, total, unrealized losses (37,286) (50,835)
Corporate Securities [Member] | Wholesale/Retail Trade [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 596,682 637,121
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (21,288) (18,880)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 29,917 29,719
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (1,691) (1,930)
Available for sale securities, continuous unrealized loss position, total, fair value 626,599 666,840
Available for sale securities, continuous unrealized loss position, total, unrealized losses (22,979) (20,810)
Corporate Securities [Member] | Services, Media and Other [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 1,874,016 2,539,519
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (61,940) (82,196)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 640,141 716,857
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (59,857) (79,211)
Available for sale securities, continuous unrealized loss position, total, fair value 2,514,157 3,256,376
Available for sale securities, continuous unrealized loss position, total, unrealized losses (121,797) (161,407)
Corporate Securities [Member] | Insurance [Member]    
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]    
Held for investment securities, continuous unrealized loss position, less than 12 months, fair value 0 0
Held for investment securities, continuous unrealized loss position, less than 12 months, unrealized losses 0 0
Held for investment securities, continuous unrealized loss position, 12 months or longer, fair value 70,795 68,766
Held for investment securities, continuous unrealized loss position, 12 months or longer, unrealized losses (6,083) (8,059)
Held for investment securities, continuous unrealized loss position, total, fair value 70,795 68,766
Held for investment securities, continuous unrealized loss position, total, unrealized losses (6,083) (8,059)
Residential Mortgage Backed Securities [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 81,636 81,762
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (3,406) (3,463)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 8,197 1,853
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (757) (91)
Available for sale securities, continuous unrealized loss position, total, fair value 89,833 83,615
Available for sale securities, continuous unrealized loss position, total, unrealized losses (4,163) (3,554)
Commercial Mortgage Backed Securities [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 2,732,202 3,148,395
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (88,183) (116,938)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 931 895
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (41) (76)
Available for sale securities, continuous unrealized loss position, total, fair value 2,733,133 3,149,290
Available for sale securities, continuous unrealized loss position, total, unrealized losses (88,224) (117,014)
Other Asset Backed Securities [Member]    
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]    
Available for sale securities, continuous unrealized loss position, less than 12 months, fair value 555,010 751,533
Available for sale securities, continuous unrealized loss position, less than 12 months, unrealized losses (6,660) (12,289)
Available for sale securities, continuous unrealized loss position, 12 months or longer, fair value 108,450 146,167
Available for sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses (7,736) (8,414)
Available for sale securities, continuous unrealized loss position, total, fair value 663,460 897,700
Available for sale securities, continuous unrealized loss position, total, unrealized losses $ (14,396) $ (20,703)