Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net interest income	$ 59,997	$ 59,641	$ 57,545	$ 57,383	$ 57,272	$ 56,627	$ 57,145	$ 53,642	$ 234,566	$ 224,686	$ 200,438
Fees and other income	45,845	32,314	32,095	39,743	39,175	40,267	38,018	36,506	149,997	153,966	158,787
Total revenues	105,842	91,955	89,640	97,126	96,447	96,894	95,163	90,148	384,563	378,652	359,225
Provision/ (credit) for loan losses	93	(949)	453	(1,795)	(942)	(432)	(6,114)	(181)	(2,198)	(7,669)	(6,935)
Operating expense	63,557	68,557	64,384	70,857	93,989	69,346	67,821	68,780	267,355	299,936	264,953
Income before income taxes	42,192	24,347	24,803	28,064	3,400	27,980	33,456	21,549	119,406	86,385	101,207
Income tax expense/(benefit)	8,651	5,461	17,399	6,026	21,391	8,289	9,963	6,553	37,537	46,196	30,963
Net income from continuing operations									81,869	40,189	70,244
Less: Net income attributable to noncontrolling interests	545	924	968	1,050	1,278	1,074	1,150	966	3,487	4,468	4,157
Net income from discontinued operations	306	0	(2)	1,698	989	1,186	1,063	1,632	2,002	4,870	5,541
Net income attributable to the Company	33,302	$ 17,962	$ 6,434	$ 22,686	(18,280)	$ 19,803	$ 23,406	$ 15,662	80,384	40,591	71,628
Assets	8,494,625				8,311,744				8,494,625	8,311,744	7,970,474
Amortization of intangibles									2,929	5,601	6,282
Depreciation									10,694	8,106	6,838
Affiliate Partners (4)
Segment Reporting Information [Line Items]
Net interest income									348	145	32
Fees and other income									75,123	98,187	95,129
Total revenues									75,471	98,332	95,161
Operating expense									54,192	94,785	67,654
Income before income taxes									21,279	3,547	27,507
Income tax expense/(benefit)									5,488	10,229	9,873
Net income from continuing operations									15,791	(6,682)	17,634
Less: Net income attributable to noncontrolling interests									3,487	4,468	4,157
Net income attributable to the Company									12,304	(11,150)	13,477
Assets	55,714				144,361				55,714	144,361	172,579
Amortization of intangibles									154	2,719	3,320
Depreciation									716	1,136	1,162
Operating Segments | Private Banking
Segment Reporting Information [Line Items]
Net interest income									238,036	227,280	202,702
Fees and other income									9,366	10,856	18,947
Total revenues									247,402	238,136	221,649
Provision/ (credit) for loan losses									(2,198)	(7,669)	(6,935)
Operating expense									165,263	149,008	125,116
Income before income taxes									84,337	96,797	103,468
Income tax expense/(benefit)									16,313	43,356	33,120
Net income from continuing operations									68,024	53,441	70,348
Net income attributable to the Company									68,024	53,441	70,348
Assets	8,424,967				8,177,304				8,424,967	8,177,304	7,816,671
Depreciation									8,646	5,639	4,477
Operating Segments | Wealth Management and Trust
Segment Reporting Information [Line Items]
Fees and other income									47,000	45,813	44,401
Total revenues									47,000	45,813	44,401
Operating expense									42,987	49,287	64,844
Income before income taxes									4,013	(3,474)	(20,443)
Income tax expense/(benefit)									1,108	(509)	(8,279)
Net income from continuing operations									2,905	(2,965)	(12,164)
Net income attributable to the Company									2,905	(2,965)	(12,164)
Assets	81,568				74,128				81,568	74,128	80,501
Amortization of intangibles									2,775	2,882	2,962
Depreciation									1,332	1,331	1,145
Holding Company and Eliminations
Segment Reporting Information [Line Items]
Net interest income									(3,818)	(2,739)	(2,296)
Fees and other income									18,508	(890)	310
Total revenues									14,690	(3,629)	(1,986)
Operating expense									4,913	6,856	7,339
Income before income taxes									9,777	(10,485)	(9,325)
Income tax expense/(benefit)									14,628	(6,880)	(3,751)
Net income from continuing operations									(4,851)	(3,605)	(5,574)
Net income from discontinued operations									2,002	4,870	5,541
Net income attributable to the Company									(2,849)	1,265	(33)
Assets	$ (67,624)				$ (84,049)				(67,624)	(84,049)	(99,277)
Depreciation									$ 0	$ 0	$ 54