Other Assets - Corporate Loan (Details)	6 Months Ended
	Jun. 30, 2017 USD ($)
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Commitment to lend	$ 130,000,000
Amount drawn	$ 101,100,000
Interest coupon rate	7.73%
Remaining term	3 years
Commitment period on undrawn amount	1 year
Commitment fee income	1.00%
Allowance for loan loss	$ 0