Regulatory Capital Requirements and Other Regulatory Matters (Details) $ in Thousands	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 1,811,280	$ 1,123,740
Actual, Ratio (as a percent)	0.0947	0.1054
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 764,968	$ 426,597
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.0400	0.0400
Common Equity Tier 1 Capital Ratio
Actual, Amount (in dollars)	$ 1,811,280	$ 1,116,185
Actual, Ratio (as a percent)	12.04%	11.35%
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 1,053,063	$ 688,508
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.0700	0.0700
Tier 1 Capital Ratio
Actual, Amount (in dollars)	$ 1,811,280	$ 1,123,740
Actual, Ratio (as a percent)	0.1204	0.1142
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 1,278,719	$ 836,045
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.0850	0.0850
Total Capital Ratio
Actual, Amount (in dollars)	$ 2,454,055	$ 1,357,904
Actual, Ratio (as a percent)	0.1631	0.1381
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 1,579,594	$ 1,032,762
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.1050	0.1050
Pacific Premier Bank
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 2,081,916	$ 1,321,494
Actual, Ratio (as a percent)	0.1089	0.1239
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 764,863	$ 426,592
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.0400	0.0400
Minimum Required For Well Capitalized Requirement, Amount (in dollars)	$ 956,079	$ 533,240
Minimum Required For Well Capitalized Requirement, Ratio (as a percent)	0.0500	0.0500
Common Equity Tier 1 Capital Ratio
Actual, Amount (in dollars)	$ 2,081,916	$ 1,321,494
Actual, Ratio (as a percent)	13.84%	13.43%
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 1,053,177	$ 688,650
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.0700	0.0700
Minimum Required For Well Capitalized Requirement, Amount (in dollars)	$ 977,950	$ 639,461
Minimum Required For Well Capitalized Requirement, Ratio (as a percent)	6.50%	6.50%
Tier 1 Capital Ratio
Actual, Amount (in dollars)	$ 2,081,916	$ 1,321,494
Actual, Ratio (as a percent)	0.1384	0.1343
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 1,278,858	$ 836,218
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.0850	0.0850
Minimum Required For Well Capitalized Requirement, Amount (in dollars)	$ 1,203,631	$ 787,029
Minimum Required For Well Capitalized Requirement, Ratio (as a percent)	0.0800	0.0800
Total Capital Ratio
Actual, Amount (in dollars)	$ 2,390,954	$ 1,360,471
Actual, Ratio (as a percent)	0.1589	0.1383
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Amount (in dollars)	$ 1,579,766	$ 1,032,975
Minimum Required for Capital Adequacy Purposes Inclusive of Capital Conservation Buffer, Ratio (as a percent)	0.1050	0.1050
Minimum Required For Well Capitalized Requirement, Amount (in dollars)	$ 1,504,539	$ 983,786
Minimum Required For Well Capitalized Requirement, Ratio (as a percent)	0.1000	0.1000