Loans - Quality of Non-Covered Loans (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Covered Loans	$ 32,232,581		$ 29,821,715
Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	6,405		37,089
Non- Accrual	81,019		103,537
Loans 90 Days or Most Delinquent and Still Accruing Interest	0		0
Total Past Due	87,424		140,626
Current	32,145,157		29,681,089
Multi-Family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Covered Loans	22,862,495		20,699,927
Multi-Family | Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	2,516		33,678
Non- Accrual	29,942		58,395
Loans 90 Days or Most Delinquent and Still Accruing Interest	0		0
Total Past Due	32,458		92,073
Current	22,830,037		20,607,854
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Covered Loans	7,660,776		7,364,231
Commercial Real Estate | Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	164		1,854
Non- Accrual	28,586		24,550
Loans 90 Days or Most Delinquent and Still Accruing Interest	0		0
Total Past Due	28,750		26,404
Current	7,632,026		7,337,827
One-to-four family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Covered Loans	404,750		560,730
One-to-four family | Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	2,451		1,076
Non- Accrual	10,575		10,937
Loans 90 Days or Most Delinquent and Still Accruing Interest	0		0
Total Past Due	13,026		12,013
Current	391,724		548,717
Acquisition, Development and Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Covered Loans	310,585		344,100
Acquisition, Development and Construction | Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	2,328		2,571
Loans 90 Days or Most Delinquent and Still Accruing Interest	0		0
Total Past Due	2,328		2,571
Current	308,257		341,529
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Covered Loans	960,019	[1],[2]	813,691	[2],[3]
Commercial and Industrial | Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due			1	[3]
Non- Accrual	8,439	[1]	5,735	[3]
Loans 90 Days or Most Delinquent and Still Accruing Interest	0	[1]	0	[3]
Total Past Due	8,439	[1]	5,736	[3]
Current	951,580	[1]	807,955	[3]
Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Covered Loans	33,956		39,036
Other | Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	1,274		480
Non- Accrual	1,149		1,349
Loans 90 Days or Most Delinquent and Still Accruing Interest	0		0
Total Past Due	2,423		1,829
Current	$ 31,533		$ 37,207

[1] Includes lease financing receivables, all of which were current at September 30, 2014.

[2] Includes lease financing receivables, all of which were classified as “pass.”

[3] Includes lease financing receivables, all of which were current at December 31, 2013.