Loss Reserves (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013
Loss Reserve [Roll Forward]
Reserve at beginning of period	$ 3,061,401		$ 4,056,843
Less reinsurance recoverable	64,085		104,848
Net reserve at beginning of period	2,997,316		3,951,995
Losses and LAE incurred in respect of default notices related to:
Current year	306,386		468,332
Prior years	(42,637)	[1]	(5,850)	[1]
Subtotal	263,749		462,482
Losses and LAE paid in respect of default notices related to:
Current year	2,674		5,137
Prior years	640,560		897,178
Reinsurance terminations	0	[2]	(3,248)	[2]
Subtotal	643,234		899,067
Net reserve at end of period	2,617,831		3,515,410
Plus reinsurance recoverables	57,763		83,898
Reserve at end of period	$ 2,675,594		$ 3,599,308

[1] A negative number for prior year loss development indicates a redundancy of prior year loss reserves, and a positive number indicates a deficiency of prior year loss reserves.

[2] In a termination, the reinsurance agreement is cancelled, with no future premium ceded and funds for any incurred but unpaid losses transferred to us. The transferred funds result in an increase in our investment portfolio (including cash and cash equivalents) and a decrease in net losses paid (reduction to losses incurred). In addition, there is an offsetting decrease in the reinsurance recoverable (increase in losses incurred), and thus there is no net impact to losses incurred.