Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

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The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Investment in Limited Partnerships - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Consolidated VIE limited partnership interest	99.90%
Total assets recorded due to consolidation	$ 0
Residual interest upon dissolution of the partnership		$ 1,000,000
Other Assets
Schedule of Equity Method Investments [Line Items]
Assets representing the carrying amount of remaining partnership			$ 800,000
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Total assets recorded due to consolidation	$ 100,000	$ 100,000