Stockholders' Equity (Narrative) (Details) $ / shares in Units, $ in Millions			12 Months Ended
	Apr. 22, 2021 shares	Sep. 23, 2019 shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 shares	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Treasury stock shares			5,100,000	4,500,000
Treasury stock, Cost basis | $			$ 175.8	$ 150.7
Shares repurchased			449,876	315,851	3,611,870
Minimum risk-based capital ratio			8.00	8.00		0.080
Minimum Tier 1 common equity			4.50%	4.50%		4.50%
Minimum Tier 1 capital ratio			6.00	6.00		0.060
Minimum Tier 1 leverage capital ratio			4.00	4.00		0.040
Well capitalized total risk based capital ratio			10.00	10.00		10.0
Well capitalized Tier 1 common equity			6.50%	6.50%		6.50%
Well capitalized Tier 1 risk-based capital ratio			8.00	8.00		8.0
Well capitalized Tier 1 leverage capital ratio			5.00	5.00		5.0
Minimum requirement of capital conservation buffer ratio			2.50%
Topic 326 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital modified transition amount percentage			25.00%
Impact of modified transition amount | $			$ 24.9
Impact of modified transition amount net of tax | $			$ 44.1
Topic 326 [Member] | Regulatory Capital Transition For 2020 and 2021 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage			0.00%
Topic 326 [Member] | Regulatory Capital Three Year Transition, Year 2022 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage			25.00%
Topic 326 [Member] | Regulatory Capital Three Year Transition, Year 2023 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage			50.00%
Topic 326 [Member] | Regulatory Capital Three Year Transition, Year 2024 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage			75.00%
Topic 326 [Member] | Regulatory Capital Three Year Transition, Year 2024 and Thereafter [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage			100.00%
Bank Holding Companies and Banks that Meet Certain Criteria [Member]
Equity, Class of Treasury Stock [Line Items]
Minimum Tier 1 leverage capital ratio						0.030
Accelerated Share Repurchase Agreement | Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized for repurchase			5,500,000
Shares repurchased			4,900,000
Shares purchased average cost per share | $ / shares			$ 37.65
2018 Stock Buyback Program [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized for repurchase	4,300,000	5,500,000
Stock repurchase expiration date	Dec. 31, 2022	Dec. 31, 2020
2018 Stock Buyback Program [Member] | Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Shares repurchased			449,876
Shares purchased average cost per share | $ / shares			$ 48.45
Restricted Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares nonvested			1,100,000	1,700,000