Equity Other Comprehensive Income (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
Pre- tax
Pre-tax, Net change									$ (12,115)	$ 8,994	$ (18,361)
Tax effect
Tax, Net change									(3,388)	3,569	(7,313)
Net of Tax
Other comprehensive income/ (loss), net of tax									(8,727)	5,425	(11,048)
Net income attributable to the Company, before tax									117,921	86,787	102,591
Income tax expense	$ 8,651	$ 5,461	$ 17,399	$ 6,026	$ 21,391	$ 8,289	$ 9,963	$ 6,553	37,537	46,196	30,963
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
Total comprehensive income, pre-tax									105,806	95,781	84,230
Total comprehensive income, tax effect									34,149	49,765	23,650
Total comprehensive income attributable to the Company, net									71,657	46,016	60,580
Accumulated Other Comprehensive Income/ (Loss)
Net of Tax
Other comprehensive income/ (loss), net of tax									(8,727)	5,425	(11,048)
Unrealized gain/ (loss) on securities available-for-sale
Pre- tax
Pre-tax, Net gains/ (losses) arising during period									(13,205)	7,782	(18,913)
Pre-tax, Adjustment for realized gains/ (losses), net									(596)	376	521
Pre-tax, Net change									(12,609)	7,406	(19,434)
Tax effect
Tax, Net gains/ (losses) arising during period									(3,702)	3,063	(7,555)
Tax, Adjustment for realized gains/ (losses), net									(170)	154	190
Tax, Net change									(3,532)	2,909	(7,745)
Net of Tax
Net of tax, Net gains/ (losses) arising during period									(9,503)	4,719	(11,358)
Net of tax, Adjustment for realized gains/ (losses), net									(426)	222	331
Other comprehensive income/ (loss), net of tax									(9,077)	4,497	(11,689)
Unrealized gain/ (loss) on cash flow hedges, after 2017-12 adoption
Pre- tax
Pre-tax, Net gains/ (losses) arising during period									985
Pre-tax, Adjustment for realized gains/ (losses), net									907
Pre-tax, Net change									78
Tax effect
Tax, Net gains/ (losses) arising during period									285
Tax, Adjustment for realized gains/ (losses), net									261
Tax, Net change									24
Net of Tax
Net of tax, Net gains/ (losses) arising during period									700
Net of tax, Adjustment for realized gains/ (losses), net									646
Other comprehensive income/ (loss), net of tax									54
Unrealized gain/ (loss) on cash flow hedges, before 2017-12 adoption
Pre- tax
Pre-tax, Net gains/ (losses) arising during period										325	(793)
Pre-tax, Adjustment for realized gains/ (losses), net										(1,179)	(1,666)
Pre-tax, Net change										1,504	873
Tax effect
Tax, Net gains/ (losses) arising during period										135	(332)
Tax, Adjustment for realized gains/ (losses), net										(491)	(687)
Tax, Net change										626	355
Net of Tax
Net of tax, Net gains/ (losses) arising during period										190	(461)
Net of tax, Adjustment for realized gains/ (losses), net										(688)	(979)
Other comprehensive income/ (loss), net of tax										878	518
Unrealized gain/ (loss) on other
Pre- tax
Pre-tax, Net gains/ (losses) arising during period									416	84	200
Pre-tax, Net change									416	84	200
Tax effect
Tax, Net gains/ (losses) arising during period									120	34	77
Tax, Net change									120	34	77
Net of Tax
Net of tax, Net gains/ (losses) arising during period									296	50	123
Other comprehensive income/ (loss), net of tax									$ 296	$ 50	$ 123