Regulatory Capital Requirements and Other Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 1,112,132	$ 737,173
Actual, Ratio (as a percent)	10.38%	10.61%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 428,751	$ 277,900
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)	$ 1,087,164	$ 717,145
Actual, Ratio (as a percent)	10.88%	10.48%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 449,505	$ 307,818
Minimum Required for Capital Adequacy Purposes (as a percent)	4.50%	4.50%
Tier 1 Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 1,112,132	$ 737,173
Actual, Ratio (as a percent)	11.13%	10.78%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 599,340	$ 410,424
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	6.00%	6.00%
Total Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 1,237,315	$ 852,382
Actual, Ratio (as a percent)	12.39%	12.46%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 799,120	$ 547,232
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)	$ 1,185,544	$ 805,110
Actual, Ratio (as a percent)	11.06%	11.59%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 428,703	$ 277,870
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)	$ 535,879	$ 347,337
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)	$ 1,185,544	$ 805,110
Actual, Ratio (as a percent)	11.87%	11.77%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 449,481	$ 307,742
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)	$ 649,251	$ 444,516
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)	$ 1,185,544	$ 805,110
Actual, Ratio (as a percent)	11.87%	11.77%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 599,308	$ 410,322
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)	$ 799,078	$ 547,096
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)	$ 1,226,258	$ 835,945
Actual, Ratio (as a percent)	12.28%	12.22%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 799,078	$ 547,096
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)	$ 998,847	$ 683,870
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	10.00%	10.00%