Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0000019612 (http://www.sec.gov/CIK)

Income Tax Disclosure [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Income Tax Disclosure [Abstract]
Provision for Federal Income Taxes Components	The current and deferred components of the provision for income taxes were as follows:     Years Ended December 31, (Dollars in thousands)   2016   2015   2014 Current income tax expense (benefit)             Federal   $ 19,144   $ 31,300   $ 29,200 State   (423 )   —   — Total current income tax expense   18,721   31,300   29,200 Deferred expense (benefit)             Federal   23,649   5,700   (1,700 ) State   442   —   — Total deferred income tax expense (benefit)   24,091   5,700   (1,700 ) Change in valuation allowance   (706 )   —   — Income tax provision   $ 42,106   $ 37,000   $ 27,500
Schedule of Federal Effective Income Tax Rate Reconciliation	A reconciliation of expected income tax expense at the federal statutory income tax rate and the amounts recorded in the Consolidated Financial Statements were as follows:     Years Ended December 31,     2016   2015   2014 (Dollars in thousands)   Amount   Rate   Amount   Rate   Amount   Rate Tax at statutory rate   $ 52,548   35.0  %   $ 43,341   35.0  %   $ 31,367   35.0  % Changes resulting from:                         Tax-exempt interest income   (5,320 )   (3.5 )   (3,943 )   (3.2 )   (3,142 )   (3.5 ) State taxes, net of federal benefit   13   —   —   —   —   — Change in valuation allowance   (706 )   (0.5 )   —   —   —   — Bank-owned life insurance adjustments   (832 )   (0.6 )   (124 )   (0.1 )   (95 )   (0.1 ) Director plan change in control   (508 )   (0.3 )   —   —   —   — Income tax credits, net   (2,454 )   (1.6 )   (2,557 )   (2.1 )   (1,624 )   (1.8 ) Nondeductible transaction expenses   2,100   1.4   411   0.3   403   0.4 Tax benefits in excess of compensation costs on share-based payments(1)   (2,240 )   (1.5 )   —   —   —   — Other, net   (495 )   (0.4 )   (128 )   —   591   0.7 Income tax expense   $ 42,106   28.0  %   $ 37,000   29.9  %   $ 27,500   30.7  % (1)The year ended December 31, 2016 reflects the impact of the early adoption of ASU 2016-09 which resulted in excess tax benefits recognized within "Income tax expense" rather than previously recognized directly into equity with "Additional paid-in-capital." Refer to Note 1, Summary of Significant Accounting Policies, for further details.
Schedule of Deferred Tax Assets and Liabilities	The significant components of the deferred tax assets and liabilities at December 31, 2016 and 2015 were as follows:     December 31, (Dollars in thousands)   2016   2015 Deferred tax assets:         Allowance for loan losses   $ 45,763   $ 24,863 Acquisition-related fair value adjustments   62,078   29,280 Accrued stock-based compensation   18,891   3,240 Loss and tax credit carry forwards   47,977   7,235 Acquisition built in loss carry forward   28,469   — Depreciation   3,896   4,333 Nonaccrual loan interest   9,465   4,994 Accrued expense   20,858   13,296 Other   7,401   5,951 Total deferred tax assets   244,798   93,192 Deferred tax liabilities:         Loan servicing rights   20,450   3,893 Core deposit intangible assets   11,844   7,379 Goodwill   6,373   5,808 Other   (715 )   4,742 Total deferred tax liabilities   37,952   21,822 Net deferred tax asset before valuation allowance   206,846   71,370 Valuation allowance   (2,239 )   (1,180 ) Net deferred tax asset   $ 204,607   $ 70,190
Summary of the loss attributes, Section 382 limitations, and tax expiration periods	The following table is a summary of the loss attributes, Section 382 limitations, and tax expiration periods as of December 31, 2016.   From the Acquisition of:                   Talmer's Prior Ownership Changes         (Dollars in thousands) Talmer   Monarch   First Place Holdings/First Place Bank   Talmer West Bank   First of Huron Corp./Signature Bank   From 2009 Ownership change   Not Limited by Section 382   Total Tax Loss and Credit Carryforwards as of 12/31/16:                               Years Expiring (except AMT Credits) 2032-2034   2026-2034   2026-2031   2030-2035   2031-2033   2027-2029   2033-2035     Annual Section 382 limitation-base(1) $ 34,668   $ 673   $ 6,650   $ 3,028   $ 365   $ 145   $ —   N/A Gross Federal Net Operating Losses 17,723   17,744   1,222   50,086   1,014   1,885   —   89,674 Gross Capital Losses 797   —   —   —   —   —   —   797 Realized Built-in Losses —   —   71,805   8,936   —   —   —   80,741 Business Tax Credits 170   1,651   781   —   —   —   592   3,194 Less amounts not recorded due to Sec 382 Limitation —   (1,738 )   —   (2,992 )   —   (145 )   —   (4,875 ) Alternative Minimum Tax Credits - no expiration 12,473   106   2,115   —   303   —   730   15,727 Valuation Allowance —   —   (66 )   (1,287 )   —   —   —   (1,353 ) (1)In respect to the Monarch and Talmer acquisitions, in addition to the statutory "base" Section 382 limitation, recognized built in gain increases the Section 382 limitation during the five year period beginning on the acquisition date. The Corporation estimates that the recognized built in gain will total $5.6 million and $322.3 million for the Monarch and Talmer acquisitions, respectively.