Derivative Financial Instruments (Risk Management Objective of Using Derivatives) (Narrative) (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Interest expense (reduction) related to previous fair value hedges		$ 4,265,000	$ 4,280,000	$ 3,124,000
Designated as Hedging Instrument [Member] | Interest Expense [Member] | Fair Value Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Interest expense (reduction) related to previous fair value hedges	$ 0		$ (1,100,000)	$ (3,400,000)