Shareholders' Equity - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Mar. 11, 2016
Stockholders Equity [Line items]
Capital conservation buffer rate	1.875%	1.25%
Reclassification adjustment from accumulated other comprehensive loss to retained earnings		$ 8,500,000
Dividends on common stock [Abstract]
Dividend potential for next fiscal year	$ 66,000,000
Period for which retained net income considered for approval	2 years
Common Stock [Member]
Dividends on common stock [Abstract]
Amount of stock authorized for repurchase				$ 100,000,000
Repurchase shares of common stock, value	$ 62,400,000		$ 750,000
Repurchase shares of common stock	2,000,000	0	34,000