Loans Receivable and Allowance for Loan Losses (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012
Loans receivable and allowance for loan losses
30-59 Days Past Due	$ 92,633		$ 115,982
60-89 Days Past Due	29,575		26,750
90 Days or More	38,170		250,534
Total Past Due	160,378		393,266
Current	11,849,581		11,993,112
Total loans	12,009,959		12,386,378
Net unamortized premiums and deferred loan origination costs	51,663		55,688
Loans receivable	12,061,622		12,442,066
Allowance for loan losses	(118,600)	(134,000)	(139,000)	(143,900)	(144,250)	(145,501)
Loans receivable, net	11,943,022		12,303,066
Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	86,551		107,754
60-89 Days Past Due	27,018		24,154
90 Days or More			384
Total Past Due	113,569		132,292
Current	11,786,663		11,922,468
Total loans	11,900,232		12,054,760
Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	6,082		8,228
60-89 Days Past Due	2,557		2,596
90 Days or More	38,170		250,150
Total Past Due	46,809		260,974
Current	62,918		70,644
Total loans	109,727		331,618
Consumer and Other Loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	2,934		3,177
60-89 Days Past Due	524		1,340
90 Days or More	5,685		5,948
Total Past Due	9,143		10,465
Current	230,086		229,216
Total loans	239,229		239,681
Allowance for loan losses	(9,540)	(10,007)	(8,824)	(7,605)	(6,357)	(6,316)
Consumer and Other Loans | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	2,934		3,177
60-89 Days Past Due	524		1,340
Total Past Due	3,458		4,517
Current	230,007		229,184
Total loans	233,465		233,701
Consumer and Other Loans | Non-accrual loans
Loans receivable and allowance for loan losses
90 Days or More	5,685		5,948
Total Past Due	5,685		5,948
Current	79		32
Total loans	5,764		5,980
Consumer and Other Loans | Home equity lines of credit
Loans receivable and allowance for loan losses
30-59 Days Past Due	2,820		3,000
60-89 Days Past Due	505		1,321
90 Days or More	5,648		5,916
Total Past Due	8,973		10,237
Current	179,848		189,572
Total loans	188,821		199,809
Consumer and Other Loans | Home equity lines of credit | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	2,820		3,000
60-89 Days Past Due	505		1,321
Total Past Due	3,325		4,321
Current	179,769		189,540
Total loans	183,094		193,861
Consumer and Other Loans | Home equity lines of credit | Non-accrual loans
Loans receivable and allowance for loan losses
90 Days or More	5,648		5,916
Total Past Due	5,648		5,916
Current	79		32
Total loans	5,727		5,948
Consumer and Other Loans | Other Loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	114		177
60-89 Days Past Due	19		19
90 Days or More	37		32
Total Past Due	170		228
Current	50,238		39,644
Total loans	50,408		39,872
Consumer and Other Loans | Other Loans | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	114		177
60-89 Days Past Due	19		19
Total Past Due	133		196
Current	50,238		39,644
Total loans	50,371		39,840
Consumer and Other Loans | Other Loans | Non-accrual loans
Loans receivable and allowance for loan losses
90 Days or More	37		32
Total Past Due	37		32
Total loans	37		32
Mortgage Loans (Gross)
Loans receivable and allowance for loan losses
30-59 Days Past Due	89,699		112,805
60-89 Days Past Due	29,051		25,410
90 Days or More	32,485		244,586
Total Past Due	151,235		382,801
Current	11,619,495		11,763,896
Total loans	11,770,730		12,146,697
Mortgage Loans (Gross) | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	83,617		104,577
60-89 Days Past Due	26,494		22,814
90 Days or More			384
Total Past Due	110,111		127,775
Current	11,556,656		11,693,284
Total loans	11,666,767		11,821,059
Mortgage Loans (Gross) | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	6,082		8,228
60-89 Days Past Due	2,557		2,596
90 Days or More	32,485		244,202
Total Past Due	41,124		255,026
Current	62,839		70,612
Total loans	103,963		325,638
Mortgage Loans (Gross) | Residential
Loans receivable and allowance for loan losses
30-59 Days Past Due	85,973		96,302
60-89 Days Past Due	23,435		22,393
90 Days or More	21,723		234,378
Total Past Due	131,131		353,073
Current	7,193,543		7,684,203
Total loans	7,324,674		8,037,276
Allowance for loan losses	(56,552)	(74,717)	(80,337)	(78,788)	(91,546)	(89,267)
Mortgage Loans (Gross) | Residential | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	81,427		90,108
60-89 Days Past Due	22,447		20,154
90 Days or More			151
Total Past Due	103,874		110,413
Current	7,138,089		7,621,388
Total loans	7,241,963		7,731,801
Mortgage Loans (Gross) | Residential | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	4,546		6,194
60-89 Days Past Due	988		2,239
90 Days or More	21,723		234,227
Total Past Due	27,257		242,660
Current	55,454		62,815
Total loans	82,711		305,475
Mortgage Loans (Gross) | Residential | Full documentation interest-only loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	20,408		29,476
60-89 Days Past Due	5,986		5,802
90 Days or More	5,565		78,271
Total Past Due	31,959		113,549
Current	1,060,257		1,268,652
Total loans	1,092,216		1,382,201
Mortgage Loans (Gross) | Residential | Full documentation interest-only loans | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	18,647		27,291
60-89 Days Past Due	5,809		5,220
Total Past Due	24,456		32,511
Current	1,040,211		1,249,462
Total loans	1,064,667		1,281,973
Mortgage Loans (Gross) | Residential | Full documentation interest-only loans | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	1,761		2,185
60-89 Days Past Due	177		582
90 Days or More	5,565		78,271
Total Past Due	7,503		81,038
Current	20,046		19,190
Total loans	27,549		100,228
Mortgage Loans (Gross) | Residential | Full documentation amortizing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	30,647		32,516
60-89 Days Past Due	7,717		8,068
90 Days or More	6,542		42,085
Total Past Due	44,906		82,669
Current	5,117,783		5,336,788
Total loans	5,162,689		5,419,457
Mortgage Loans (Gross) | Residential | Full documentation amortizing loans | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	30,266		31,189
60-89 Days Past Due	7,717		7,415
90 Days or More			151
Total Past Due	37,983		38,755
Current	5,111,329		5,325,944
Total loans	5,149,312		5,364,699
Mortgage Loans (Gross) | Residential | Full documentation amortizing loans | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	381		1,327
60-89 Days Past Due			653
90 Days or More	6,542		41,934
Total Past Due	6,923		43,914
Current	6,454		10,844
Total loans	13,377		54,758
Mortgage Loans (Gross) | Residential | Reduced documentation interest-only loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	25,795		24,700
60-89 Days Past Due	6,138		5,787
90 Days or More	8,066		87,910
Total Past Due	39,999		118,397
Current	644,579		721,264
Total loans	684,578		839,661
Mortgage Loans (Gross) | Residential | Reduced documentation interest-only loans | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	24,048		22,635
60-89 Days Past Due	5,559		5,208
Total Past Due	29,607		27,843
Current	618,429		693,660
Total loans	648,036		721,503
Mortgage Loans (Gross) | Residential | Reduced documentation interest-only loans | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	1,747		2,065
60-89 Days Past Due	579		579
90 Days or More	8,066		87,910
Total Past Due	10,392		90,554
Current	26,150		27,604
Total loans	36,542		118,158
Mortgage Loans (Gross) | Residential | Reduced documentation amortizing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	9,123		9,610
60-89 Days Past Due	3,594		2,736
90 Days or More	1,550		26,112
Total Past Due	14,267		38,458
Current	370,924		357,499
Total loans	385,191		395,957
Mortgage Loans (Gross) | Residential | Reduced documentation amortizing loans | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	8,466		8,993
60-89 Days Past Due	3,362		2,311
Total Past Due	11,828		11,304
Current	368,120		352,322
Total loans	379,948		363,626
Mortgage Loans (Gross) | Residential | Reduced documentation amortizing loans | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	657		617
60-89 Days Past Due	232		425
90 Days or More	1,550		26,112
Total Past Due	2,439		27,154
Current	2,804		5,177
Total loans	5,243		32,331
Mortgage Loans (Gross) | Multi-Family
Loans receivable and allowance for loan losses
30-59 Days Past Due	2,091		13,844
60-89 Days Past Due	3,549		1,327
90 Days or More	10,324		9,054
Total Past Due	15,964		24,225
Current	3,567,644		3,272,230
Total loans	3,583,608		3,296,455
Allowance for loan losses	(37,075)	(34,578)	(36,703)	(40,865)	(33,952)	(35,514)
Mortgage Loans (Gross) | Multi-Family | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	2,009		12,740
60-89 Days Past Due	3,549		970
Total Past Due	5,558		13,710
Current	3,564,810		3,270,206
Total loans	3,570,368		3,283,916
Mortgage Loans (Gross) | Multi-Family | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	82		1,104
60-89 Days Past Due			357
90 Days or More	10,324		9,054
Total Past Due	10,406		10,515
Current	2,834		2,024
Total loans	13,240		12,539
Mortgage Loans (Gross) | Commercial Real Estate
Loans receivable and allowance for loan losses
30-59 Days Past Due	1,635		2,659
60-89 Days Past Due	2,067		1,690
90 Days or More	438		1,154
Total Past Due	4,140		5,503
Current	858,308		807,463
Total loans	862,448		812,966
Allowance for loan losses	(15,433)	(14,698)	(13,136)	(16,642)	(12,395)	(14,404)
Mortgage Loans (Gross) | Commercial Real Estate | Accruing loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	181		1,729
60-89 Days Past Due	498		1,690
90 Days or More			233
Total Past Due	679		3,652
Current	853,757		801,690
Total loans	854,436		805,342
Mortgage Loans (Gross) | Commercial Real Estate | Non-accrual loans
Loans receivable and allowance for loan losses
30-59 Days Past Due	1,454		930
60-89 Days Past Due	1,569
90 Days or More	438		921
Total Past Due	3,461		1,851
Current	4,551		5,773
Total loans	$ 8,012		$ 7,624