Acquired Loans - Changes in the Carrying Value of Acquired Loans (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Apr. 07, 2017
Carrying value of acquired loans [Abstract]
Carrying value, net, beginning		$ 260,850
Additions					$ 7,900
Accretion to interest income		14,924	$ 18,405	$ 30,501
Carrying value, net, ending		257,438	260,850
Acquired Not ASC 310-30 [Member]
Carrying value of acquired loans [Abstract]
Carrying value, net, beginning	[1]	42,743	67,657
Transfers	[1],[2]	(36,719)
Additions	[1],[3]	109,548
Accretion to interest income	[1]	1,578	40
Payments received, net	[1]	(39,208)	(24,953)
Other	[1],[4]	(74)	0
Change in allowance for loan losses, acquired loans	[1]	0	(1)
Carrying value, net, ending	[1]	77,868	42,743	67,657
Acquired Impaired [Member]
Carrying value of acquired loans [Abstract]
Carrying value, net, beginning		218,107	310,762
Transfers	[2]	0
Additions	[3]	7,899
Accretion to interest income		14,924	18,405
Payments received, net		(68,317)	(111,522)
Other	[4]	(361)	(134)
Change in allowance for loan losses, acquired loans		7,318	596
Carrying value, net, ending		$ 179,570	$ 218,107	$ 310,762

[1] “Acquired Not ASC 310-30” loans consist of loans that are not in scope for FASB ASC Topic 310-30.

[2] “Acquired Not ASC 310-20” loans transferred to LHFI due to the discount on these loans being fully amortized.

[3] Loans acquired in the Reliance merger on April 7, 2017

[4] Includes miscellaneous timing adjustments as well as acquired loan terminations through foreclosure, charge-off and other terminations.