Deposits (Balances for Core Deposits and Time Deposits) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Core Deposits
Noninterest-bearing demand	$ 11,377,009	$ 10,887,306
Interest-bearing checking	4,584,447	4,419,089
Money market	8,262,677	8,359,425
Savings	2,146,429	2,308,494
Total core deposits	26,370,562	25,974,314
Time deposits:
Less than $100,000	1,957,121	1,176,973
$100,000 or greater	7,111,945	4,463,776
Total time deposits	9,069,066	5,640,749
Total deposits	35,439,628	31,615,063
Hong Kong and China
Time deposits:
Total time deposits	1,210,000	841,300
Interest-bearing demand deposit	621,300	456,400
Geographic Distribution, Foreign \| Hong Kong and China
Time deposits:
Time deposits, at or above FDIC insurance limit	1,190,000	814,600
Geographic Distribution, Domestic \| United States
Time deposits:
Time deposits, at or above FDIC insurance limit	$ 4,450,000	$ 2,370,000

The aggregate of all deposit liabilities held by the entity excluding time deposits.

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Core Deposits [Abstract]

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Core Deposits [Line Items]

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- Definition

Amount of interest-bearing checking deposit liabilities.

+ References

No definition available.

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- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
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Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts.

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Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).

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Amount of money in interest-bearing foreign accounts that entitle the depositor to withdraw funds at any time without prior notice, also known as demand deposits. Checking and negotiable order withdrawals (NOW) are the most common forms of demand deposits.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 235
-Section S99
-Paragraph 1
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The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.

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- Definition

Amount of time deposit liabilities, including certificates of deposit.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more.

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-Publisher SEC
-Name Industry Guide
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-Section V
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Amount of time deposit liabilities, including certificates of deposit, in denominations that meet or exceed the Federal Deposit Insurance Corporation (FDIC) insurance limit.

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Amount of time deposit liabilities, including certificates of deposit, in denominations of less than $100,000.

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