Regulatory Capital Requirements and Other Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 744,233	$ 366,658
Actual, Ratio (as a percent)	10.70%	9.78%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 278,183	$ 150,027
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Common Equity Tier 1 to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 724,205	$ 356,658
Actual, Ratio (as a percent)	10.59%	10.12%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 307,778	$ 158,574
Minimum Required for Capital Adequacy Purposes (as a percent)	4.50%	4.50%
Tier 1 Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 744,233	$ 366,658
Actual, Ratio (as a percent)	10.88%	10.41%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 410,371	$ 211,432
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	6.00%	6.00%
Total Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 859,442	$ 448,150
Actual, Ratio (as a percent)	12.57%	12.72%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 547,161	$ 281,909
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Pacific Premier Bank
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 812,170	$ 410,524
Actual, Ratio (as a percent)	11.68%	10.94%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 278,152	$ 150,107
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 347,690	$ 187,634
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	5.00%	5.00%
Common Equity Tier 1 to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 812,170	$ 410,524
Actual, Ratio (as a percent)	11.88%	11.65%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 307,702	$ 158,536
Minimum Required for Capital Adequacy Purposes (as a percent)	4.50%	4.50%
Required to be Well Capitalized Under Prompt Corrective Action Regulations (in dollars)	$ 444,458	$ 228,997
Required to be Well Capitalized Under Prompt Corrective Action Regulations (as a percent)	6.50%	6.50%
Tier 1 Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 812,170	$ 410,524
Actual, Ratio (as a percent)	11.88%	11.65%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 410,269	$ 211,382
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	6.00%	6.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 547,025	$ 281,842
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	8.00%	8.00%
Total Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 843,005	$ 432,943
Actual, Ratio (as a percent)	12.33%	12.29%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 547,025	$ 281,842
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 683,781	$ 352,303
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	10.00%	10.00%