XML 78 R29.htm IDEA: XBRL DOCUMENT
v3.19.3

Investment Securities (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2019
Investment Securities |
Schedule of amortized cost and fair value of securities | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | September 30, 2019 | ​ | December 31, 2018
​ | ​ | Amortized | ​ | Unrealized | ​ | Unrealized | ​ | Fair | ​ | Amortized | ​ | Unrealized | ​ | Unrealized | ​ | Fair
(dollars in thousands) |  | Cost |  | Gains |  | Losses |  | Value |  | Cost |  | Gains |  | Losses |  | Value
U.S. Treasury securities | ​ | $ | 29,653 | ​ | $ | 85 | ​ | $ | — | ​ | $ | 29,738 | ​ | $ | 389,470 | ​ | $ | — | ​ | $ | — | ​ | $ | 389,470
Government agency debt securities | ​ | ​ | 24,387 | ​ | ​ | 85 | ​ | ​ | — | ​ | ​ | 24,472 | ​ | ​ | — | ​ | ​ | — | ​ | ​ | — | ​ | ​ | —
Government-sponsored enterprises debt securities | ​ | ​ | 126,696 | ​ | ​ | 28 | ​ | ​ | (75) | ​ | ​ | 126,649 | ​ | ​ | 248,372 | ​ | ​ | — | ​ | ​ | (6,778) | ​ | ​ | 241,594
Government agency mortgage-backed securities | ​ | ​ | 342,326 | ​ | ​ | 2,738 | ​ | ​ | (1,159) | ​ | ​ | 343,905 | ​ | ​ | 426,710 | ​ | ​ | — | ​ | ​ | (15,174) | ​ | ​ | 411,536
Government-sponsored enterprises mortgage-backed securities | ​ | ​ | 366,346 | ​ | ​ | 6,831 | ​ | ​ | (1,228) | ​ | ​ | 371,949 | ​ | ​ | 156,056 | ​ | ​ | 85 | ​ | ​ | (5,294) | ​ | ​ | 150,847
Collateralized mortgage obligations: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Government agency | ​ | ​ | 2,479,961 | ​ | ​ | 13,900 | ​ | ​ | (7,337) | ​ | ​ | 2,486,524 | ​ | ​ | 2,779,620 | ​ | ​ | — | ​ | ​ | (97,171) | ​ | ​ | 2,682,449
Government-sponsored enterprises | ​ | ​ | 773,755 | ​ | ​ | 3,964 | ​ | ​ | (3,874) | ​ | ​ | 773,845 | ​ | ​ | 620,337 | ​ | ​ | — | ​ | ​ | (17,745) | ​ | ​ | 602,592
Debt securities issued by states and political subdivisions | ​ | ​ | — | ​ | ​ | — | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 19,854 | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 19,854
Total available-for-sale securities | ​ | $ | 4,143,124 | ​ | $ | 27,631 | ​ | $ | (13,673) | ​ | $ | 4,157,082 | ​ | $ | 4,640,419 | ​ | $ | 85 | ​ | $ | (142,162) | ​ | $ | 4,498,342
Schedule of amortized cost and fair value of debt securities by contractual maturity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | September 30, 2019
​ | ​ | Amortized | ​ | Fair
(dollars in thousands) |  | Cost |  | Value
Due in one year or less | ​ | $ | 29,653 | ​ | $ | 29,738
Due after one year through five years | ​ | ​ | 126,696 | ​ | ​ | 126,649
Due after five years through ten years | ​ | ​ | — | ​ | ​ | —
Due after ten years | ​ | ​ | — | ​ | ​ | —
​ | ​ | ​ | 156,349 | ​ | ​ | 156,387
​ | ​ | ​ | ​ | ​ | ​ | ​
Government agency debt securities | ​ | ​ | 24,387 | ​ | ​ | 24,472
Government agency mortgage-backed securities | ​ | ​ | 342,326 | ​ | ​ | 343,905
Government-sponsored enterprises mortgage-backed securities | ​ | ​ | 366,346 | ​ | ​ | 371,949
Collateralized mortgage obligations: | ​ | ​ | ​ | ​ | ​ | ​
Government agency | ​ | ​ | 2,479,961 | ​ | ​ | 2,486,524
Government-sponsored enterprises | ​ | ​ | 773,755 | ​ | ​ | 773,845
Total collateralized mortgage obligations | ​ | ​ | 3,253,716 | ​ | ​ | 3,260,369
Total available-for-sale securities | ​ | $ | 4,143,124 | ​ | $ | 4,157,082
Schedule of gross unrealized losses and fair values of securities in a continuous loss position | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Time in Continuous Loss as of September 30, 2019
​ | ​ | Less Than 12 Months | ​ | 12 Months or More | ​ | Total
​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​
(dollars in thousands) |  | Losses |  | Fair Value |  | Losses |  | Fair Value |  | Losses |  | Fair Value
Government-sponsored enterprises debt securities | ​ | $ | (75) | ​ | $ | 24,917 | ​ | $ | — | ​ | $ | — | ​ | $ | (75) | ​ | $ | 24,917
Government agency mortgage-backed securities | ​ | ​ | — | ​ | ​ | — | ​ | ​ | (1,159) | ​ | ​ | 115,069 | ​ | ​ | (1,159) | ​ | ​ | 115,069
Government-sponsored enterprises mortgage-backed securities | ​ | ​ | — | ​ | ​ | — | ​ | ​ | (1,228) | ​ | ​ | 115,456 | ​ | ​ | (1,228) | ​ | ​ | 115,456
Collateralized mortgage obligations: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Government agency | ​ | ​ | (820) | ​ | ​ | 407,961 | ​ | ​ | (6,517) | ​ | ​ | 652,211 | ​ | ​ | (7,337) | ​ | ​ | 1,060,172
Government-sponsored enterprises | ​ | ​ | (161) | ​ | ​ | 107,250 | ​ | ​ | (3,713) | ​ | ​ | 226,823 | ​ | ​ | (3,874) | ​ | ​ | 334,073
Total available-for-sale securities with unrealized losses | ​ | $ | (1,056) | ​ | $ | 540,128 | ​ | $ | (12,617) | ​ | $ | 1,109,559 | ​ | $ | (13,673) | ​ | $ | 1,649,687
​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Time in Continuous Loss as of December 31, 2018
​ | ​ | Less Than 12 Months | ​ | 12 Months or More | ​ | Total
​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​
(dollars in thousands) |  | Losses |  | Fair Value |  | Losses |  | Fair Value |  | Losses |  | Fair Value
Government-sponsored enterprises debt securities | ​ | $ | — | ​ | $ | — | ​ | $ | (6,778) | ​ | $ | 157,939 | ​ | $ | (6,778) | ​ | $ | 157,939
Government agency mortgage-backed securities | ​ | ​ | — | ​ | ​ | — | ​ | ​ | (15,174) | ​ | ​ | 373,891 | ​ | ​ | (15,174) | ​ | ​ | 373,891
Government-sponsored enterprises mortgage-backed securities | ​ | ​ | (1) | ​ | ​ | 172 | ​ | ​ | (5,293) | ​ | ​ | 125,869 | ​ | ​ | (5,294) | ​ | ​ | 126,041
Collateralized mortgage obligations: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Government agency | ​ | ​ | — | ​ | ​ | — | ​ | ​ | (97,171) | ​ | ​ | 2,475,532 | ​ | ​ | (97,171) | ​ | ​ | 2,475,532
Government-sponsored enterprises | ​ | ​ | — | ​ | ​ | — | ​ | ​ | (17,745) | ​ | ​ | 486,175 | ​ | ​ | (17,745) | ​ | ​ | 486,175
Total available-for-sale securities with unrealized losses | ​ | $ | (1) | ​ | $ | 172 | ​ | $ | (142,161) | ​ | $ | 3,619,406 | ​ | $ | (142,162) | ​ | $ | 3,619,578

X
- Definition Tabular disclosure of fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=118942371&loc=SL82922954-210456 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
Name: | us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration