Investments Schedule of Available for sale Securities (Details) - USD ($) $ in Thousands		Dec. 31, 2016		Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis		$ 1,283,161		$ 1,084,105
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		4,635		7,634
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax		23,664		7,229
Available-for-sale Securities		1,264,132		1,084,510
Held-to-maturity Securities		93,079		116,352
Held-to-maturity Securities, Fair Value		92,604		116,384
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		1		294
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		476		262
US Government and Government Agencies and Authorities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis		40,704	[1]	21,214
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		86		64
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax		854		27
Available-for-sale Securities		39,936	[1]	21,251
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis		337,865	[1]	345,033
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		1,058		874
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax		2,259		1,345
Available-for-sale Securities		336,664	[1]	344,562
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis		296,271	[1]	263,661
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		2,116		5,099
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax		4,990		116
Available-for-sale Securities		293,397	[1]	268,644
Mortgage Backed Securities, Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	[2]	584,960	[3]	431,446
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	[2]	928		1,329
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	[2]	15,561		5,734
Available-for-sale Securities	[2]	570,327	[3]	427,041
Held-to-maturity Securities	[2]	93,079	[3]	116,352
Held-to-maturity Securities, Fair Value	[2]	92,604	[3]	116,384
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	[2]	1		294
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	[2]	476		262
Other Aggregated Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis		23,361	[4]	22,751
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		447		268
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax		0		7
Available-for-sale Securities		$ 23,808	[4]	$ 23,012

[1] Certain securities are callable before their final maturity.

[2] All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.

[3] Mortgage-backed securities are shown based on their final (contractual) maturity, but, due to prepayments, they are expected to have shorter lives.

[4] Other securities consist of money market mutual funds and equity securities held by certain Wealth Advisory and Investment Management businesses.