Noncontrolling Interest Noncontrolling Interest - Other Common Units (Details) $ in Millions		6 Months Ended
	May 31, 2017 USD ($) shares	Jun. 30, 2017
San Diego, CA, Q2 2017 [Member]
Noncontrolling Interest [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	687,827
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned | $	$ 18.6
Business Acquisition, Equity Interest Issued or Issuable, Basis for Determining Value, Trailing Average Common Stock Price Period	5 days
Other Common Units
Noncontrolling Interest [Line Items]
Unit conversion ratio		1
Other Common Units | San Diego, CA, Q2 2017 [Member]
Noncontrolling Interest [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	687,827
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned | $	$ 18.6