Derivative Instruments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 310,000	$ 355,000
Not Designated as Hedging Instrument [Member]
Interest rate swap agreements [Abstract]
Notional amount of interest rate swap		792,224	502,642
Estimated fair value of interest rate swap		(199)	(405)
Pay Fixed / Receive Variable Swaps [Member] | Not Designated as Hedging Instrument [Member]
Interest rate swap agreements [Abstract]
Notional amount of interest rate swap		396,112	251,321
Estimated fair value of interest rate swap		16,130	13,030
Pay Variable / Receive Fixed Swaps [Member] | Not Designated as Hedging Instrument [Member]
Interest rate swap agreements [Abstract]
Notional amount of interest rate swap		396,112	251,321
Estimated fair value of interest rate swap		$ (16,329)	$ (13,435)
Interest Rate Swap April 2016 April 2020 [Member]
Forward cash flow hedge relationship [Abstract]
Term, lower maturity range date	[1]	Apr. 01, 2016	Apr. 01, 2016
Term, higher maturity range date	[1]	Apr. 01, 2020	Apr. 01, 2020
Interest rate derivative assets, at fair value		$ (784)	$ (96)
Unrealized gain in accumulated other comprehensive income		(476)	(58)
Interest Rate Swap April 2016 April 2020 [Member] | Designated as Hedging Instrument [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 33,000	$ 33,000
Variable interest rate		3 month LIBOR	3 month LIBOR
Fixed interest rate		2.265%	2.265%
Interest Rate Swap April 2016 April 2022 [Member]
Forward cash flow hedge relationship [Abstract]
Term, lower maturity range date	[1]	Apr. 01, 2016	Apr. 01, 2016
Term, higher maturity range date	[1]	Apr. 01, 2022	Apr. 01, 2022
Interest rate derivative assets, at fair value		$ (1,478)	$ (531)
Unrealized gain in accumulated other comprehensive income		(898)	(323)
Interest Rate Swap April 2016 April 2022 [Member] | Designated as Hedging Instrument [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 34,000	$ 34,000
Variable interest rate		3 month LIBOR	3 month LIBOR
Fixed interest rate		2.646%	2.646%
Interest Rate Swap October 2016 October 2020 [Member]
Forward cash flow hedge relationship [Abstract]
Term, lower maturity range date	[1]	Oct. 01, 2016	Oct. 01, 2016
Term, higher maturity range date	[1]	Oct. 01, 2020	Oct. 01, 2020
Interest rate derivative assets, at fair value		$ (908)	$ (210)
Unrealized gain in accumulated other comprehensive income		(552)	(128)
Interest Rate Swap October 2016 October 2020 [Member] | Designated as Hedging Instrument [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 34,000	$ 34,000
Variable interest rate		3 month LIBOR	3 month LIBOR
Fixed interest rate		2.523%	2.523%
Interest Rate Swap July 2014 July 2021 [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 27,500	$ 27,500
Variable interest rate		1 month LIBOR	1 month LIBOR
Fixed interest rate		2.09%	2.09%
Term, lower maturity range date	[1]	Jul. 01, 2014	Jul. 01, 2014
Term, higher maturity range date	[1]	Jul. 01, 2021	Jul. 01, 2021
Interest rate derivative assets, at fair value		$ 663	$ 941
Unrealized gain in accumulated other comprehensive income		403	572
Interest Rate Swap July 2014 July 2022 [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 25,000	$ 27,500
Variable interest rate		1 month LIBOR	1 month LIBOR
Fixed interest rate		2.27%	2.27%
Term, lower maturity range date	[1]	Jul. 01, 2014	Jul. 01, 2014
Term, higher maturity range date	[1]	Jul. 01, 2022	Jul. 01, 2022
Interest rate derivative assets, at fair value		$ 968	$ 409
Unrealized gain in accumulated other comprehensive income		588	249
Interest Rate Swap July 2014 July 2023 [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 27,500	$ 27,500
Variable interest rate		1 month LIBOR	1 month LIBOR
Fixed interest rate		2.42%	2.42%
Term, lower maturity range date	[1]	Jul. 01, 2014	Jul. 01, 2014
Term, higher maturity range date	[1]	Jul. 01, 2023	Jul. 01, 2023
Interest rate derivative assets, at fair value		$ 1,320	$ 651
Unrealized gain in accumulated other comprehensive income		802	396
Interest Rate Swap July 2014 July 2024 [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 30,000	$ 27,500
Variable interest rate		1 month LIBOR	1 month LIBOR
Fixed interest rate		2.50%	2.50%
Term, lower maturity range date	[1]	Jul. 01, 2014	Jul. 01, 2014
Term, higher maturity range date	[1]	Jul. 01, 2024	Jul. 01, 2024
Interest rate derivative assets, at fair value		$ 1,333	$ 956
Unrealized gain in accumulated other comprehensive income		$ 810	$ 581
Interest Rate Swap October 2017 October 2021 [Member]
Forward cash flow hedge relationship [Abstract]
Term, lower maturity range date	[1]	Oct. 01, 2017	Oct. 01, 2017
Term, higher maturity range date	[1]	Oct. 01, 2021	Oct. 01, 2021
Interest rate derivative assets, at fair value		$ (1,112)	$ (517)
Unrealized gain in accumulated other comprehensive income		(676)	(314)
Interest Rate Swap October 2017 October 2021 [Member] | Designated as Hedging Instrument [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 33,000	$ 33,000
Variable interest rate		3 month LIBOR	3 month LIBOR
Fixed interest rate		2.992%	2.992%
Interest Rate Swap April 2018 July 2022 [Member]
Forward cash flow hedge relationship [Abstract]
Term, lower maturity range date	[1]	Apr. 01, 2018	Apr. 01, 2018
Term, higher maturity range date	[1]	Jul. 01, 2022	Jul. 01, 2022
Interest rate derivative assets, at fair value		$ (1,170)	$ (590)
Unrealized gain in accumulated other comprehensive income		(711)	(359)
Interest Rate Swap April 2018 July 2022 [Member] | Designated as Hedging Instrument [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 33,000	$ 33,000
Variable interest rate		3 month LIBOR	3 month LIBOR
Fixed interest rate		3.118%	3.118%
Interest Rate Swap July 2018 October 2022 [Member]
Forward cash flow hedge relationship [Abstract]
Term, lower maturity range date	[1]	Jul. 01, 2018	Jul. 01, 2018
Term, higher maturity range date	[1]	Oct. 01, 2022	Oct. 01, 2022
Interest rate derivative assets, at fair value		$ (1,158)	$ (602)
Unrealized gain in accumulated other comprehensive income		(704)	(366)
Interest Rate Swap July 2018 October 2022 [Member] | Designated as Hedging Instrument [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 33,000	$ 33,000
Variable interest rate		3 month LIBOR	3 month LIBOR
Fixed interest rate		3.158%	3.158%
Interest Rate Swap August 2015 - August 2018 [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 15,000
Variable interest rate		2 month LIBOR
Fixed interest rate		1.048%
Term, lower maturity range date	[1]	Aug. 01, 2015
Term, higher maturity range date	[1]	Aug. 01, 2018
Interest rate derivative assets, at fair value		$ (46)
Unrealized gain in accumulated other comprehensive income		(28)
Interest Rate Swap August 2015 - August 2019 [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 15,000
Variable interest rate		3 month LIBOR
Fixed interest rate		1.281%
Term, lower maturity range date	[1]	Aug. 02, 2015
Term, higher maturity range date	[1]	Aug. 01, 2019
Interest rate derivative assets, at fair value		$ (34)
Unrealized gain in accumulated other comprehensive income		(21)
Interest Rate Swap August 2015 - August 2020 [Member]
Forward cash flow hedge relationship [Abstract]
Forecasted notional amount		$ 15,000
Variable interest rate		4 month LIBOR
Fixed interest rate		1.47%
Term, lower maturity range date	[1]	Aug. 03, 2015
Term, higher maturity range date	[1]	Aug. 01, 2020
Interest rate derivative assets, at fair value		$ (14)
Unrealized gain in accumulated other comprehensive income		$ (9)

[1] No cash will be exchanged prior to the term.