Regulatory Capital Requirements and Other Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 1,123,740	$ 1,112,132
Actual, Ratio (as a percent)	10.54%	10.38%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 426,597	$ 428,751
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 426,597	$ 428,751
Minimum Required Plus Capital Conservation Buffer Fully Phased-In Ratio (as a percent)	4.00%	4.00%
Common Equity Tier 1 Capital Ratio
Actual, Amount (in dollars)	$ 1,116,185	$ 1,087,164
Actual, Ratio (as a percent)	11.35%	10.88%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 442,612	$ 449,505
Minimum Required for Capital Adequacy Purposes (as a percent)	4.50%	4.50%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 688,508	$ 699,230
Minimum Required Plus Capital Conservation Buffer Fully Phased-In Ratio (as a percent)	7.00%	7.00%
Tier 1 Capital to Ratio
Actual, Amount (in dollars)	$ 1,123,740	$ 1,112,132
Actual, Ratio (as a percent)	11.42%	11.13%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 590,149	$ 599,340
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	6.00%	6.00%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 836,045	$ 849,065
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Ratio (as a percent)	8.50%	8.50%
Total Capital Ratio
Actual, Amount (in dollars)	$ 1,357,904	$ 1,237,315
Actual, Ratio (as a percent)	13.81%	12.39%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 786,866	$ 799,120
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 1,032,762	$ 1,048,845
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Ratio (as a percent)	10.50%	10.50%
Pacific Premier Bank
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 1,321,494	$ 1,185,544
Actual, Ratio (as a percent)	12.39%	11.06%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 426,592	$ 428,703
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 426,592	$ 428,703
Minimum Required Plus Capital Conservation Buffer Fully Phased-In Ratio (as a percent)	4.00%	4.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 533,240	$ 535,879
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	5.00%	5.00%
Common Equity Tier 1 Capital Ratio
Actual, Amount (in dollars)	$ 1,321,494	$ 1,185,544
Actual, Ratio (as a percent)	13.43%	11.87%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 442,704	$ 449,481
Minimum Required for Capital Adequacy Purposes (as a percent)	4.50%	4.50%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 688,650	$ 699,193
Minimum Required Plus Capital Conservation Buffer Fully Phased-In Ratio (as a percent)	7.00%	7.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations (in dollars)	$ 639,461	$ 649,251
Required to be Well Capitalized Under Prompt Corrective Action Regulations (as a percent)	6.50%	6.50%
Tier 1 Capital to Ratio
Actual, Amount (in dollars)	$ 1,321,494	$ 1,185,544
Actual, Ratio (as a percent)	13.43%	11.87%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 590,272	$ 599,308
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	6.00%	6.00%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 836,218	$ 849,020
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Ratio (as a percent)	8.50%	8.50%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 787,029	$ 799,078
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	8.00%	8.00%
Total Capital Ratio
Actual, Amount (in dollars)	$ 1,360,471	$ 1,226,258
Actual, Ratio (as a percent)	13.83%	12.28%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 787,029	$ 799,078
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Amount (in dollars)	$ 1,032,975	$ 1,048,790
Minimum Required Plus Capital Conservation Buffer Fully Phased-In, Ratio (as a percent)	10.50%	10.50%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 983,786	$ 998,847
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	10.00%	10.00%