Investments - Schedule of Securities Related to Unrecognized OTTI (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) security	Dec. 31, 2015 USD ($) security	Dec. 31, 2014 USD ($)
Securities in Continuous Unrealized Loss Positions
Securities in unrealized loss position | security	165	168
Available for sale securities in continuous unrealized loss position, Fair Value, Less than 12 months	$ 30,675	$ 49,316
Available for sale securities in continuous unrealized loss position, Fair Value, 12 months or greater	995	995
Available for sale securities in continuous unrealized loss position, Fair Value	31,670	50,311
Available for sale securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	565	628
Available for sale securities in continuous unrealized loss position, Unrealized loss, 12 months or greater	7	7
Available for sale securities in continuous unrealized loss position, Unrealized loss	572	635
HTM securities in continuous unrealized loss position, Fair Value, Less than 12 months	251,986	284,151
HTM securities in continuous unrealized loss position, Fair value, 12 months or greater	53,032	780
HTM securities in continuous unrealized loss position, Fair Value, Total	305,018	284,931
HTM securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	2,984	2,071
HTM securities in continuous unrealized loss position, Unrealized loss, 12 months or greater	597	85
HTM securities in continuous unrealized loss position, Unrealized loss, Total	3,581	2,156
Mortgage-backed securities
Securities in Continuous Unrealized Loss Positions
HTM securities in continuous unrealized loss position, Fair Value, Less than 12 months	217,604	281,547
HTM securities in continuous unrealized loss position, Fair value, 12 months or greater	52,332
HTM securities in continuous unrealized loss position, Fair Value, Total	269,936	281,547
HTM securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	2,107	2,059
HTM securities in continuous unrealized loss position, Unrealized loss, 12 months or greater	424
HTM securities in continuous unrealized loss position, Unrealized loss, Total	2,531	2,059
Trust preferred securities
Securities in Continuous Unrealized Loss Positions
Available for sale securities in continuous unrealized loss position, Fair Value, Less than 12 months	14,979	15,294
Available for sale securities in continuous unrealized loss position, Fair Value, 12 months or greater	995	995
Available for sale securities in continuous unrealized loss position, Fair Value	15,974	16,289
Available for sale securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	526	439
Available for sale securities in continuous unrealized loss position, Unrealized loss, 12 months or greater	7	7
Available for sale securities in continuous unrealized loss position, Unrealized loss	533	446
HTM securities in continuous unrealized loss position, Fair Value, Less than 12 months	4,175	780
HTM securities in continuous unrealized loss position, Fair value, 12 months or greater	700
HTM securities in continuous unrealized loss position, Fair Value, Total	4,875	780
HTM securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	94
HTM securities in continuous unrealized loss position, Unrealized loss, 12 months or greater	173	85
HTM securities in continuous unrealized loss position, Unrealized loss, Total	267	85
Corporate debt securities
Securities in Continuous Unrealized Loss Positions
Available for sale securities in continuous unrealized loss position, Fair Value, Less than 12 months	14,482	33,591
Available for sale securities in continuous unrealized loss position, Fair Value	14,482	33,591
Available for sale securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	21	169
Available for sale securities in continuous unrealized loss position, Unrealized loss	21	169
Municipal securities
Securities in Continuous Unrealized Loss Positions
Available for sale securities in continuous unrealized loss position, Fair Value, Less than 12 months	1,214	431
Available for sale securities in continuous unrealized loss position, Fair Value	1,214	431
Available for sale securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	18	20
Available for sale securities in continuous unrealized loss position, Unrealized loss	18	20
HTM securities in continuous unrealized loss position, Fair Value, Less than 12 months	30,207	2,604
HTM securities in continuous unrealized loss position, Fair Value, Total	30,207	2,604
HTM securities in continuous unrealized loss position, Unrealized loss, Less than 12 months	783	12
HTM securities in continuous unrealized loss position, Unrealized loss, Total	783	12
Debt securities
Securities in Continuous Unrealized Loss Positions
Credit component of OTTI recognized in earnings	$ 0	$ 0	$ 0