Stockholders' Equity (Narrative) (Details) - USD ($)
$ / shares in Units, $ in Millions

1 Months Ended

9 Months Ended

Aug. 05, 2019

Sep. 30, 2019

Jul. 31, 2019

Jun. 30, 2019

Jan. 31, 2019

Sep. 30, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Dec. 31, 2017

Equity [Abstract]

Redeemable Noncontrolling Interest [Table Text Block]

The following table shows the changes in redeemable noncontrolling interest in equity of consolidated subsidiary during the three and nine months ended September 30, 2019 (in thousands):

	Three Months Ended September 30, 2019			Nine Months Ended September 30, 2019
Redeemable noncontrolling interest, beginning of period	$	12,509		$	8,531
Net income attributable to redeemable noncontrolling interest partner	863			2,528
Distributions of income to redeemable noncontrolling interest partner	—			(527		)
Accretion of redeemable noncontrolling interest	(1,163		)	1,677
Redeemable noncontrolling interest, end of period	$	12,209		$	12,209

Class of Stock [Line Items]

Stock Repurchased During Period, Shares

63,417

144,584

39,320

7,862

Stock Repurchased During Period, Value

$ 0.6

$ 1.2

$ 0.3

$ 0.1

Common stock, shares authorized (in shares)

100,000,000

100,000,000

100,000,000

Common stock, par value (in dollars per share)

$ 0.01

$ 0.01

$ 0.01

Common Stock, Shares, Issued

50,879,949

50,879,949

50,879,949

50,719,884

50,719,884

50,719,884

50,598,901

Common stock, shares outstanding (in shares)

50,488,010

50,488,010

50,583,128

Preferred stock, shares authorized (in shares)

5,000,000

5,000,000

5,000,000

Preferred stock, par value (in dollars per share)

$ 0.01

$ 0.01

$ 0.01

Preferred stock, shares issued (in shares)

0

0

0

Preferred stock, shares outstanding (in shares)

0

0

0

Stock Repurchase Program Expiration Date

Aug. 05, 2019

Stock Repurchase Program, Remaining Authorized Repurchase Amount

$ 26.8

$ 26.8

GHO Homes [Member]

Class of Stock [Line Items]

Ownership percentage by noncontrolling owners

20.00%

20.00%