Regulatory Matters Capital Ratios for Company and Bank under Federal Regulatory Guidelines, Compared to Minimum Regulatory Capital Requirements for Adequately Capitalized and Well Capitalized Depository Institution (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
SVB Financial Group
CET 1 risk-based capital, actual ratio	12.28%
CET 1 risk-based capital, well capitalized minimum ratio	6.50%
CET 1 risk-based capital, adequately capitalized minimum ratio	4.50%
CET 1 risk-based capital, actual amount	$ 3,183,206
CET 1 risk-based capital, well capitalized minimum amount	1,684,774
CET 1 risk-based capital, adequately capitalized minimum amount	$ 1,166,382
Tier 1 risk-based capital, actual ratio	12.83%	12.91%
Tier 1 risk-based capital, well capitalized minimum ratio	8.00%	6.00%
Tier 1 risk-based capital, adequately capitalized minimum ratio	6.00%	4.00%
Tier 1 risk-based capital, actual amount	$ 3,325,245	$ 2,808,948
Tier 1 risk-based capital, well capitalized minimum amount	2,073,567	1,305,726
Tier 1 risk-based capital, adequately capitalized minimum amount	$ 1,555,176	$ 870,484
Total risk-based capital, actual ratio	13.84%	13.92%
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	$ 3,586,466	$ 3,030,150
Total risk-based capital, well capitalized minimum amount	2,591,959	2,176,210
Total risk-based capital, adequately capitalized minimum amount	$ 2,073,567	$ 1,740,968
Tier 1 leverage, actual ratio	7.63%	7.74%
Tier 1 leverage, adequately capitalized minimum ratio	4.00%	4.00%
Tier 1 leverage, actual amount	$ 3,325,245	$ 2,808,948
Tier 1 leverage, adequately capitalized minimum amount	$ 1,743,555	$ 1,450,927
Silicon Valley Bank
CET 1 risk-based capital, actual ratio	12.52%
CET 1 risk-based capital, well capitalized minimum ratio	6.50%
CET 1 risk-based capital, adequately capitalized minimum ratio	4.50%
CET 1 risk-based capital, actual amount	$ 3,043,435
CET 1 risk-based capital, well capitalized minimum amount	1,579,568
CET 1 risk-based capital, adequately capitalized minimum amount	$ 1,093,547
Tier 1 risk-based capital, actual ratio	12.52%	11.09%
Tier 1 risk-based capital, well capitalized minimum ratio	8.00%	6.00%
Tier 1 risk-based capital, adequately capitalized minimum ratio	6.00%	4.00%
Tier 1 risk-based capital, actual amount	$ 3,043,435	$ 2,379,991
Tier 1 risk-based capital, well capitalized minimum amount	1,944,083	1,287,473
Tier 1 risk-based capital, adequately capitalized minimum amount	$ 1,458,063	$ 858,315
Total risk-based capital, actual ratio	13.60%	12.12%
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	$ 3,304,537	$ 2,600,011
Total risk-based capital, well capitalized minimum amount	2,430,104	2,145,788
Total risk-based capital, adequately capitalized minimum amount	$ 1,944,083	$ 1,716,630
Tier 1 leverage, actual ratio	7.09%	6.64%
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	$ 3,043,435	$ 2,379,991
Tier 1 leverage, well capitalized minimum amount	2,147,532	1,793,264
Tier 1 leverage, adequately capitalized minimum amount	$ 1,718,026	$ 1,434,611