XML 63 R68.htm IDEA: XBRL DOCUMENT

Investments - Summary of Sources of Collateral Received and Various Investment Agreement in which Collateral Pledged (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Cash and Securities Pledged Directly from Investment Portfolio [Member]
Derivative [Line Items]
Fair Value of Cash and Underlying Securities	$ 609,439	$ 646,663
Fair Value of Cash and Securities Pledged to Investment and Repurchase Agreement Counterparties	376,014	375,412
Fair Value of Cash and Securities Pledged to Derivative Counterparties	233,425	271,251
Cash and Securities Pledged from its Derivative Counterparties [Member]
Derivative [Line Items]
Fair Value of Cash and Underlying Securities
Fair Value of Cash and Securities Pledged to Investment and Repurchase Agreement Counterparties
Fair Value of Cash and Securities Pledged to Derivative Counterparties