Allowance for Loan and Lease Losses (Summary of Changes in the Allowance for Loan and Lease Losses and Recorded Investments by Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in allowance for loan losses
Balance at the beginning of the period				$ 58,692				$ 58,592	$ 58,692	$ 58,592	$ 53,666
Charge-offs									(9,038)	(7,228)	(15,811)
Recoveries									1,867	2,577	1,953
Provision for loan and lease losses									9,561	4,751	18,784
Balance at the end of the period	$ 61,082				$ 58,692				61,082	58,692	58,592
Provisions for credit losses
Total provision (credit) for loan and lease losses									9,561	4,751	18,784
Unfunded credit commitments									22	200	204
Total provision (credit) for credit losses	3,602	$ 871	$ 3,757	1,353	123	$ 2,717	$ 1,470	641	9,583	4,951	18,988
Commercial Real Estate
Changes in allowance for loan losses
Balance at the beginning of the period				28,187				27,112	28,187	27,112	27,645
Charge-offs									0	(103)	(494)
Recoveries									0	0	476
Provision for loan and lease losses									2,098	1,178	(515)
Balance at the end of the period	30,285				28,187				30,285	28,187	27,112
Provisions for credit losses
Total provision (credit) for loan and lease losses									2,098	1,178	(515)
Commercial
Changes in allowance for loan losses
Balance at the beginning of the period				25,283				26,333	25,283	26,333	20,906
Charge-offs									(8,911)	(6,585)	(14,914)
Recoveries									1,688	2,287	1,158
Provision for loan and lease losses									6,766	3,248	19,183
Balance at the end of the period	24,826				25,283				24,826	25,283	26,333
Provisions for credit losses
Total provision (credit) for loan and lease losses									6,766	3,248	19,183
Consumer
Changes in allowance for loan losses
Balance at the beginning of the period				$ 5,222				$ 5,147	5,222	5,147	5,115
Charge-offs									(127)	(540)	(403)
Recoveries									179	290	319
Provision for loan and lease losses									697	325	116
Balance at the end of the period	$ 5,971				$ 5,222				5,971	5,222	5,147
Provisions for credit losses
Total provision (credit) for loan and lease losses									697	325	116
Originated
Changes in allowance for loan losses
Provision for loan and lease losses									9,050	4,509	18,829
Provisions for credit losses
Total provision (credit) for loan and lease losses									9,050	4,509	18,829
Unfunded credit commitments									22	200	204
Total provision (credit) for credit losses									9,072	4,709	19,033
Originated | Commercial Real Estate
Changes in allowance for loan losses
Provision for loan and lease losses									1,798	254	(343)
Provisions for credit losses
Total provision (credit) for loan and lease losses									1,798	254	(343)
Originated | Commercial
Changes in allowance for loan losses
Provision for loan and lease losses									6,539	3,699	18,899
Provisions for credit losses
Total provision (credit) for loan and lease losses									6,539	3,699	18,899
Originated | Consumer
Changes in allowance for loan losses
Provision for loan and lease losses									713	556	273
Provisions for credit losses
Total provision (credit) for loan and lease losses									713	556	273
Acquired
Changes in allowance for loan losses
Provision for loan and lease losses									511	242	(45)
Provisions for credit losses
Total provision (credit) for loan and lease losses									511	242	(45)
Unfunded credit commitments									0	0	0
Total provision (credit) for credit losses									511	242	(45)
Acquired | Commercial Real Estate
Changes in allowance for loan losses
Provision for loan and lease losses									300	924	(172)
Provisions for credit losses
Total provision (credit) for loan and lease losses									300	924	(172)
Acquired | Commercial
Changes in allowance for loan losses
Provision for loan and lease losses									227	(451)	284
Provisions for credit losses
Total provision (credit) for loan and lease losses									227	(451)	284
Acquired | Consumer
Changes in allowance for loan losses
Provision for loan and lease losses									(16)	(231)	(157)
Provisions for credit losses
Total provision (credit) for loan and lease losses									$ (16)	$ (231)	$ (157)