Acquisitions	3 Months Ended
Mar. 31, 2018
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS Completed Acquisitions Standard Bancshares, Inc. On January 6, 2017, the Company completed its acquisition of Standard Bancshares, Inc. ("Standard"), the holding company for Standard Bank and Trust Company. Pursuant to the terms of the merger agreement, on January 6, 2017, each outstanding share of Standard common stock was canceled and converted into the right to receive 0.4350 of a share of Company common stock. Based on the closing price of shares of Company common stock of $25.34 on that date, as reported by NASDAQ, the value of the merger consideration per share of Standard common stock was $11.02. Each outstanding Standard stock settled right was redeemed for cash, and each outstanding Standard stock option and each share of Standard phantom stock was canceled and terminated in exchange for the right to receive cash, in each case, pursuant to the terms of the merger agreement. This resulted in an overall transaction value of approximately $580.7 million, which consisted of 21,057,085 shares of Company common stock and $47.1 million in cash. Goodwill of $345.3 million associated with the acquisition was recorded by the Company. All operating systems were converted during the first quarter of 2017. During 2017, the Company finalized the fair value adjustments associated with the Standard transactions. Premier Asset Management LLC On February 28, 2017, the Company completed its acquisition of Premier Asset Management LLC ("Premier"), a registered investment advisor based in Chicago, Illinois. At the close of the acquisition, the Company acquired approximately $550.0 million of trust assets under management. During the first quarter of 2018, the Company finalized the fair value adjustments associated with the Premier transaction, which required a measurement period adjustment of $1.9 million to increase goodwill. This adjustment was recognized in the current period in accordance with accounting guidance applicable to business combinations.

ACQUISITIONS

Completed Acquisitions

Standard Bancshares, Inc.

On January 6, 2017, the Company completed its acquisition of Standard Bancshares, Inc. ("Standard"), the holding company for Standard Bank and Trust Company. Pursuant to the terms of the merger agreement, on January 6, 2017, each outstanding share of Standard common stock was canceled and converted into the right to receive 0.4350 of a share of Company common stock. Based on the closing price of shares of Company common stock of $25.34 on that date, as reported by NASDAQ, the value of the merger consideration per share of Standard common stock was $11.02. Each outstanding Standard stock settled right was redeemed for cash, and each outstanding Standard stock option and each share of Standard phantom stock was canceled and terminated in exchange for the right to receive cash, in each case, pursuant to the terms of the merger agreement. This resulted in an overall transaction value of approximately $580.7 million, which consisted of 21,057,085 shares of Company common stock and $47.1 million in cash. Goodwill of $345.3 million associated with the acquisition was recorded by the Company. All operating systems were converted during the first quarter of 2017.

During 2017, the Company finalized the fair value adjustments associated with the Standard transactions.

Premier Asset Management LLC

On February 28, 2017, the Company completed its acquisition of Premier Asset Management LLC ("Premier"), a registered investment advisor based in Chicago, Illinois. At the close of the acquisition, the Company acquired approximately $550.0 million of trust assets under management.

During the first quarter of 2018, the Company finalized the fair value adjustments associated with the Premier transaction, which required a measurement period adjustment of $1.9 million to increase goodwill. This adjustment was recognized in the current period in accordance with accounting guidance applicable to business combinations.