Regulatory Matters - Capital Ratios for Company and Bank under Federal Regulatory Guidelines (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
SVB Financial Group
CET 1 risk-based capital, actual ratio	13.41%	12.78%
CET 1 risk-based capital, well capitalized minimum ratio	6.50%	6.50%
CET 1 risk-based capital, adequately capitalized minimum ratio	4.50%	4.50%
CET 1 risk-based capital, actual amount	$ 5,167,270	$ 4,182,315
CET 1 risk-based capital, well capitalized minimum amount	2,504,310	2,127,902
CET 1 risk-based capital, adequately capitalized minimum amount	$ 1,733,753	$ 1,473,163
Tier 1 risk-based capital, actual ratio	13.58%	12.97%
Tier 1 risk-based capital, well capitalized minimum ratio	8.00%	8.00%
Tier 1 risk-based capital, adequately capitalized minimum ratio	6.00%	6.00%
Tier 1 risk-based capital, actual amount	$ 5,231,476	$ 4,246,606
Tier 1 risk-based capital, well capitalized minimum amount	3,082,228	2,618,957
Tier 1 risk-based capital, adequately capitalized minimum amount	$ 2,311,671	$ 1,964,218
Total risk-based capital, actual ratio	14.45%	13.96%
Total risk-based capital, well capitalized minimum ratio	10.00%	10.00%
Total risk-based capital, adequately capitalized minimum ratio	8.00%	8.00%
Total risk-based capital, actual amount	$ 5,567,562	$ 4,571,542
Total risk-based capital, well capitalized minimum amount	3,852,785	3,273,696
Total risk-based capital, adequately capitalized minimum amount	$ 3,082,228	$ 2,618,957
Tier 1 leverage, actual ratio	9.06%	8.34%
Tier 1 leverage, adequately capitalized minimum ratio	4.00%	4.00%
Tier 1 leverage, actual amount	$ 5,231,476	$ 4,246,606
Tier 1 leverage, adequately capitalized minimum amount	$ 2,308,592	$ 2,036,138
Silicon Valley Bank
CET 1 risk-based capital, actual ratio	12.41%	12.06%
CET 1 risk-based capital, well capitalized minimum ratio	6.50%	6.50%
CET 1 risk-based capital, adequately capitalized minimum ratio	4.50%	4.50%
CET 1 risk-based capital, actual amount	$ 4,604,689	$ 3,787,988
CET 1 risk-based capital, well capitalized minimum amount	2,411,765	2,041,227
CET 1 risk-based capital, adequately capitalized minimum amount	$ 1,669,684	$ 1,413,157
Tier 1 risk-based capital, actual ratio	12.41%	12.06%
Tier 1 risk-based capital, well capitalized minimum ratio	8.00%	8.00%
Tier 1 risk-based capital, adequately capitalized minimum ratio	6.00%	6.00%
Tier 1 risk-based capital, actual amount	$ 4,604,689	$ 3,787,988
Tier 1 risk-based capital, well capitalized minimum amount	2,968,326	2,512,279
Tier 1 risk-based capital, adequately capitalized minimum amount	$ 2,226,245	$ 1,884,209
Total risk-based capital, actual ratio	13.32%	13.04%
Total risk-based capital, well capitalized minimum ratio	10.00%	10.00%
Total risk-based capital, adequately capitalized minimum ratio	8.00%	8.00%
Total risk-based capital, actual amount	$ 4,940,776	$ 4,094,782
Total risk-based capital, well capitalized minimum amount	3,710,408	3,140,349
Total risk-based capital, adequately capitalized minimum amount	$ 2,968,326	$ 2,512,279
Tier 1 leverage, actual ratio	8.10%	7.56%
Tier 1 leverage, well capitalized minimum ratio	5.00%	5.00%
Tier 1 leverage, adequately capitalized minimum ratio	4.00%	4.00%
Tier 1 leverage, actual amount	$ 4,604,689	$ 3,787,988
Tier 1 leverage, well capitalized minimum amount	2,841,139	2,504,636
Tier 1 leverage, adequately capitalized minimum amount	$ 2,272,912	$ 2,003,709

Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets

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Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets, Actual Amount

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Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets, Adequately Capitalized Amount

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Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets Required to be Adequately Capitalized

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Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets Required to be Well Capitalized

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Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets, Well Capitalized Amount

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The amount of total capital as defined in the regulations.

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The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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Tier 1 Risk Based Capital as defined in the regulations.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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