Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income before noncontrolling interests	$ 1,184,717	$ 1,011,348	$ 519,178
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	106,416	87,870	92,304
Gains on investment securities, net	(134,670)	(88,094)	(45,547)
Distributions of earnings from non-marketable and other equity securities	95,131	72,015	45,867
Depreciation and amortization	82,717	57,906	56,123
Amortization of premiums and discounts on investment securities, net	15,513	(28)	2,530
Amortization of share-based compensation	66,815	45,675	36,900
Amortization of deferred loan fees	(155,429)	(128,077)	(111,738)
Deferred income tax (benefit) expense	(3,072)	(21,061)	25,187
Excess tax benefit from exercise of stock options and vesting of restricted shares	(9,588)	(17,989)	(18,014)
Losses from the write-off of premises and equipment	5,219	7,278	0
Other losses (gains)	8,959	0	(3,308)
Changes in other assets and liabilities:
Accrued interest receivable and payable, net	(24,189)	(55,834)	(31,372)
Accounts receivable and payable, net	(17,019)	(23,020)	3,481
Income tax receivable and payable, net	(11,630)	(5,820)	46,168
Accrued compensation	(15,253)	56,874	31,689
Foreign exchange spot contracts, net	59,998	24,018	(20,891)
Other, net	(74,240)	(54,039)	15,909
Net cash provided by operating activities	1,164,129	933,562	646,865
Cash flows from investing activities:
Purchases of available-for-sale securities	(9,872,095)	(668,264)	(2,420,741)
Proceeds from sales of available-for-sale securities	2,189,087	474,482	580,871
Proceeds from maturities and paydowns of available-for-sale securities	1,643,357	3,436,064	3,339,574
Purchases of held-to-maturity securities	(492,502)	(4,726,595)	(5,967,223)
Proceeds from maturities and paydowns of held-to-maturity securities	2,124,513	1,891,761	1,708,001
Purchases of non-marketable and other equity securities	(136,186)	(81,574)	(44,047)
Proceeds from sales and distributions of capital of non-marketable and other equity securities	113,526	95,025	51,052
Net increase in loans	(4,773,775)	(5,175,409)	(3,170,099)
Purchases of premises and equipment	(65,479)	(45,865)	(50,884)
Proceeds from sale of equity valuation services business	0	0	3,000
Acquisition of SVB Leerink	(102,328)	0	0
Net cash used for investing activities	(9,371,882)	(4,800,375)	(5,970,496)
Cash flows from financing activities:
Net increase in deposits	12,428,907	5,074,825	5,274,207
Net (decrease) increase in short-term borrowings	(613,982)	(402,318)	521,062
Principal payments of long-term debt	(358,395)	0	(97,781)
(Distributions to noncontrolling interests), net of contributions from noncontrolling interests	(50,978)	(28,494)	(23,535)
Net proceeds from the issuance of preferred stock	340,138	0	0
Common stock repurchase	(352,511)	(147,123)	0
Proceeds from issuance of common stock, ESPP and ESOP	24,818	18,387	27,003
Net cash provided by financing activities	11,417,997	4,515,277	5,700,956
Net increase in cash and cash equivalents	3,210,244	648,464	377,325
Cash and cash equivalents at beginning of period	3,571,539	2,923,075	2,545,750
Cash and cash equivalents at end of period	6,781,783	3,571,539	2,923,075
Cash paid during the period for:
Interest	217,961	75,601	45,592
Income taxes	422,346	376,425	277,823
Noncash items during the period:
Changes in unrealized gains and losses on available-for-sale securities, net of tax	139,934	(15,498)	(24,788)
Distributions of stock from investments	8,917	5,277	6,807
Equity warrant assets
Adjustments to reconcile net income to net cash provided by operating activities:
Changes in fair value of derivatives	2,240	(24,417)	(11,862)
Derivative
Adjustments to reconcile net income to net cash provided by operating activities:
Changes in fair value of derivatives	$ (18,506)	$ (11,043)	$ 14,261