Minimum Regulatory Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2021

Banking and Thrift, Interest [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations

The Company’s actual capital amounts and ratios are presented in the following table:

	Actual				For Capital Adequacy				To Be Well- Capitalized Under Prompt Corrective Action Provisions
	Amount		Ratio		Amount		Ratio		Amount		Ratio
	(Dollars in thousands)
As of December 31, 2021
Total regulatory capital (to risk-weighted assets)	$	2,939,016	19.77	%	$	1,189,466	≥8	%	$	1,486,832	≥10	%
Common equity Tier 1 capital (to risk-weighted assets)	2,831,102		19.04		892,099		4.5		1,189,466		6.5
Tier 1 capital (to risk-weighted assets)	2,831,102		19.04		669,075		6		966,441		8
Tier I capital (to average assets)	2,831,102		13.96		811,000		4		1,013,750		5
As of December 31, 2020
Total regulatory capital (to risk-weighted assets)	$	3,135,445	29.61	%	$	847,069	≥8	%	1,058,836		≥10	%
Common equity Tier 1 capital (to risk-weighted assets)	3,013,079		28.46		476,476		4.5		688,243		6.5
Tier 1 capital (to risk-weighted assets)	3,013,079		28.46		635,302		6		847,069		8
Tier 1 capital (to average assets)	3,013,079		19.53		617,049		4		771,312		5