Shareholders' Equity - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 21, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock net issuance costs	$ 56,700	$ 55,641	$ 0	$ 0
Stock Issued During Period, Shares, New Issues	8,900,000
Capital Conservation Buffer Rate		1.25%
Parent [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Stock Issued During Period, Shares, New Issues	2,700,000
Shareholders [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Stock Issued During Period, Shares, New Issues	6,200,000
Stock Purchase Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Reserved common shares for issuance		300,000
Common shares issued as a result of employee participation, aggregate		175,997
Profit Sharing Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Reserved common shares for issuance		1,000,000
Common shares issued as a result of employee participation, aggregate		32,120